# vnigam21

Rich.C@EMPOWERgmat.com posted a reply to In a certain bathtub, both the hot and cold water fixtures in the Problem Solving forum
“Hi All, We''re told that In a certain bathtub, both the hot and cold water fixtures leak. The cold water leak alone would fill an empty bucket in C hours, and the hot water leak alone will fill the same bucket in H hours, where C < H. If both fixtures began to leak at the same time into the ...”
Yesterday
Brent@GMATPrepNow posted a reply to Problem with a practice question in the GMAT Math forum
“Here''s my full solution: https://www.beatthegmat.com/for-all-positive-integers-m-t299496.html Cheers, Brent”
Yesterday
GMATGuruNY posted a reply to Events A and B are independent and have equal probabilities in the Data Sufficiency forum
“Statement 1: P(at least one event occurs) = 1 - P(neither event occurs) Thus: P(at least A or B) = 1 - P(neither A nor B) Since P(at least A or B) = 0.84, we get: 0.84 = 1 - P(neither A nor B) P(neither A nor B) = 0.16 P(not A) * P(not B) = 0.16. Since it is given that P(A) = P(B), P(not ...”
Yesterday
GMATGuruNY posted a reply to In the given figure, if AS = 10 cm, SN = 5 cm and TN = 8 cm, in the Problem Solving forum
“Third-side rule: The third side a triangle must be LESS THAN THE SUM OF and GREATER THAN THE DIFFERENCE OF the other two sides. Here, all the sides must be INTEGER values. In triangle ANS, AS=10 and NS=5. Thus, third side AN must be an integer value less than 10+5 = 15 and greater than 10-5 = ...”
Yesterday
Rich.C@EMPOWERgmat.com posted a reply to If $$xy \neq 0$$, and 75 percent of $$x$$ equals 125 percent in the Problem Solving forum
“Hi All, We''re told that neither X nor Y can equal 0 and that 75% of X is equal to 125% of Y. We''re asked which of the following is true. This question can be solved in a couple of different ways, including by TESTing VALUES. IF.... X = 100, then (75% of X) = 75 75 = 125% of Y 75 = ...”
March 22, 2019
Rich.C@EMPOWERgmat.com posted a reply to If $$xy \neq 0$$ and $$2x + 3y$$ is equal to 175 percent in the Problem Solving forum
“Hi All, We''re told that neither X nor Y can be 0 and that (2X + 3Y) is 175% of 8X. We''re asked for the value of X/Y. This question can be solved in a number of different ways, including by TESTing THE ANSWERS. Between Answers B and D, Answer D would be an easier Answer to TEST, so let''s try ...”
March 22, 2019
Rich.C@EMPOWERgmat.com posted a reply to Find the range of values of $$x$$ that satisfy the in the Problem Solving forum
“Hi All, We''re asked for the range of values of X that satisfy the inequality (X+1)(X-2) > 4. This question can be approached in a couple of different ways, including by TESTing VALUES. IF... X=10, then (11)(8) = 88 which is greater than 4. Thus, X=10 is a possible solution. Eliminate ...”
March 22, 2019
Brent@GMATPrepNow posted a reply to If $$xy \neq 0$$, and 75 percent of $$x$$ equals 125 percent in the Problem Solving forum
“GIVEN: 75 percent of x equals 125 percent of y Rewrite as: 3/4 of x = 5/4 of y Or we can say: (3/4)(x) = (5/4)( y) Multiply both sides by 4 to get: 3x = 5y Divide both sides by 5 to get: 3x/5 = y Rewrite as: y = (3/5)(x) Or y = 3/5 of x Or y = 60/100 of x Or y = 60% of x Answer: C ...”
March 22, 2019
Brent@GMATPrepNow posted a reply to If m and n are prime numbers, what is the value of m+n? in the Data Sufficiency forum
“ Given: m and n are prime numbers Target question: What is the value of m+n? Statement 1: 15 ≤ m < n ≤ 20 17 and 19 are the only PRIME numbers from 15 to 20 inclusive So, it must be the case that m = 17 and n = 19 So, the answer to the target question is m+n = 17 + 19 = 33 Since ...”
March 22, 2019
GMATGuruNY posted a reply to Express 2^20-2^19-2^18-2^17 as a power of 2. in the Problem Solving forum
“Test an analogous case with easier values: 2⁴ - 2³ - 2² - 2¹ = 16 - 8 - 4 - 2 = 2¹ The matching blue portions imply the following: 2²⁰ - 2¹⁹ - 2¹⁸ - 2¹⁷ = 2¹⁷ The correct answer is C.”
March 22, 2019
OfficialGMAT posted a reply to College selection help needed in the The Application Process forum
“Hi Aswath, The GMAT School Search feature is a tool that can help you discover and connect with the schools based on your profile and preferences. If you''re looking to identify other potential programs, check out the School Search here.”
March 22, 2019
Brent@GMATPrepNow posted a reply to If n is an integer, is n + 1 odd? in the Data Sufficiency forum
“Target question: Is n + 1 odd? Some important rules: #1. ODD +/- ODD = EVEN #2. ODD +/- EVEN = ODD #3. EVEN +/- EVEN = EVEN Statement 1: n + 2 is an even integer. In other words: n + EVEN = EVEN In other words: n = EVEN - EVEN By Rule #3, n must be even, which means n+1 is ODD The ...”
March 22, 2019
Brent@GMATPrepNow posted a reply to Express 2^20-2^19-2^18-2^17 as a power of 2. in the Problem Solving forum
“2^20 - 2^19 - 2^18 - 2^17 = 2^17(2^3 - 2^2 - 2^1 - 1) = 2^17(8 - 4 - 2 - 1) = 2^17(1) = 2^17 Answer: C Cheers, Brent”
March 22, 2019
GMATGuruNY posted a reply to If (r+1/r)^2 = 5, what is the value of (r^3+1/r^3)^2? in the Problem Solving forum
“(r + 1/r)² = 5 r + 1/r = √5 (r + 1/r)² = 5 r² + 1/r² + 2(r)(1/r) = 5 r² + 1/r² + 2 = 5 r² + 1/r² = 3 Multiplying the blue equation and the red equation, we get: (r² + 1/r²)(r + 1/r) = 3√5 r³ + (r²)(1/r) + (1/r²)(r) + 1/r³ = 3√5 r³ + (r + 1/r) + 1/r³ = 3√5 ...”
March 21, 2019
GMATGuruNY posted a reply to A dessert recipe calls for 50% melted chocolate and 50% in the Problem Solving forum
“Chocolate percentage in the incorrect sauce: 40%. Chocolate percentage in the pure chocolate: 100%. Chocolate percentage in the mixture: 50%. Let I = the incorrect sauce and C = the pure chocolate. The following approach is called ALLIGATION -- a very efficient way to handle MIXTURE PROBLEMS. ...”
March 21, 2019
Brent@GMATPrepNow posted a reply to What is the total cost to make 7 long distance telephone in the Data Sufficiency forum
“Target question: What is the total cost to make 7 long distance telephone calls? When we SCAN the statements, we see the key phrase: at least This allows us to jump straight to... Statements 1 and 2 combined There are infinitely many scenarios that satisfy BOTH statements. Here are two: ...”
March 21, 2019
GMATGuruNY posted a reply to Skier Lindsey Vonn completes a straight 300-meter downhill in the Problem Solving forum
“Downhill speed - uphill speed = (x+10) - (x-8) = 18. Implication: The downhill speed is 18 mps greater than the uphill speed. We can PLUG IN THE ANSWERS, which represent the downhill speed. Since the downhill speed is 18 mps greater than the uphill speed, the correct answer must be GREATER ...”
March 21, 2019
Brent@GMATPrepNow posted a reply to Skier Lindsey Vonn completes a straight 300-meter downhill in the Problem Solving forum
“The ride up the mountain took 135 seconds longer than her run down the mountain Start with a word equation: (time going UP mountain) = (time going DOWN mountain) + 135 time = distance/speed We can now write: 300/(x - 8) = 300/(x + 10) + 135 Multiply both sides by (x - 8) to get: 300 = 300(x - ...”
March 21, 2019
GMATGuruNY posted a reply to Jeremiah invests his savings of $120,000 by dividing it in the Problem Solving forum “On the GMAT, compounded interest is typically just a bit more than simple interest. Since the answer choices are all greater than 2% -- the percentage given in the prompt -- they must represent the HIGHER interest rate, with 2% representing the LOWER interest rate. Lower rate: Since 3/4 of ...” March 21, 2019 GMATGuruNY posted a reply to If m and n are positive integers, is m+n divisible by 15? in the Data Sufficiency forum “Rule: MULTIPLE OF X + MULTIPLE OF X = MULTIPLE OF X MULTIPLE OF X + NON-MULTIPLE OF X = NON-MULTIPLE OF X 225 = 9*25 Statements combined: Case 1: m=9 and n=25*15, with the result that m is a multiple of 9, n is a multiple of 15, and mn = 9*25*15 = 225*15 = multiple of 225 In this case, m+n ...” March 21, 2019 GMATGuruNY posted a reply to What is the smallest positive integer n such that n / 420 ca in the Problem Solving forum “A fraction will yield a terminating decimal if the prime-factorization of its denominator contains only 2''s and/or 5''s. n/420 = n/(2*2*3*5*7). For a terminating decimal to be yielded, the prime factors in red must CANCEL OUT with n, leaving only 2''s and 5''s in the denominator. Thus, the ...” March 21, 2019 Brent@GMATPrepNow posted a reply to x is the product of all even numbers from 2 to 50, inclusive in the Problem Solving forum “x = (2)(4)(6)....(46)(48)(50) = (1)(2)(2)(2)(3)(2).....(23)(2)(24)(2)(25)(2) Notice that: x is divisible by 2. This tells us that x+1 is 1 greater than a multiple of 2. In other words, x+1 is NOT divisible by 2 x is divisible by 3. This tells us that x+1 is 1 greater than a multiple of 3. ...” March 20, 2019 Rich.C@EMPOWERgmat.com posted a reply to x is the product of all even numbers from 2 to 50, inclusive in the Problem Solving forum “Hi All, We''re told that X is the product of all even numbers from 2 to 50, inclusive. We''re asked to define what the smallest prime factor of (X+1) must be. This particular question is a variation on an Official question that periodically pops up in the forums. The main idea behind this prompt ...” March 20, 2019 GMATGuruNY posted a reply to The consultant explained that companies in the Sentence Correction forum “Generally, a one-word adverb such as tirelessly will not be positioned between a verb and its direct object. Incorrect: Companies lobby tirelessly government officials. Here, tirelessly (adverb) is awkwardly positioned between lobby (verb) and government officials (direct object). Correct: ...” March 20, 2019 GMATGuruNY posted a reply to one another vs. others? in the Sentence Correction forum “Some grammarians -- including me -- reserve each other for two elements and one another for more than two. Other grammarians consider the two modifiers interchangeable. A club has exactly three members: Ann, Beth, and Carol. The sentence above implies the following: Ann, Beth and Carol ...” March 20, 2019 Brent@GMATPrepNow posted a reply to If there are 4 pairs of twins, and a committee will be in the Problem Solving forum “Here''s one approach. Take the task of selecting the 3 committee members and break it into stages. Stage 1: Select the 3 twins from which we will select 1 spouse each. There are 4 sets of twins, and we must select 3 of them. Since the order in which we select the 3 twins does not matter, ...” March 20, 2019 Brent@GMATPrepNow posted a reply to If arc PQR above is a semicircle, what is the length of diam in the Data Sufficiency forum “http://s16.postimg.cc/p2mwbwdpt/triangle_PQR.jpg We can answer this question without performing any calculations. Instead, we can use some visualization. Important point: For geometry DS questions, we are typically checking to see whether the statements "lock" a particular angle or ...” March 20, 2019 GMATGuruNY posted a reply to If arc PQR above is a semicircle, what is the length of diam in the Data Sufficiency forum “An INSCRIBED ANGLE is formed by two chords. Thus, angle PQR is an inscribed angle. An inscribed angle that intercepts the diameter is a RIGHT ANGLE. Thus, angle PQR is a right angle, implying that triangle PQR is a RIGHT TRIANGLE. http://s15.postimage.org/xozmfjdh3/PQR.jpg In the figure ...” March 20, 2019 Rich.C@EMPOWERgmat.com posted a reply to A furniture store sells only two models of desks, model A in the Problem Solving forum “Hi All, We''re told that a furniture store sells only two models of desks, model A and model B. The selling price of model A is$120, which is 30 percent of the selling price of the model B - and the furniture store sells 2,000 desks, 3/4 of which are model B. We''re asked for the TOTAL revenue ...”
March 20, 2019
Brent@GMATPrepNow posted a reply to In a group of children, the average (arithmetic mean) weight in the Problem Solving forum
“We can also use weighted averages to solve this Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ... Let G = number of girls Let B = number of boys So, G+B = TOTAL number of children ...”
March 20, 2019
Rich.C@EMPOWERgmat.com posted a reply to Point A in the xy-coordinate system is shown below. Given in the Problem Solving forum
“Hi All, We''re told that Point A is in the xy-coordinate system as shown - and that two other points B (4a, b) and C (2a, 5b) are also in the system. We''re asked for the AREA of triangle ABC in terms of a and b. This question can be approached in a couple of different ways, including by TESTing ...”
March 20, 2019
Rich.C@EMPOWERgmat.com posted a reply to In a group of children, the average (arithmetic mean) weight in the Problem Solving forum
“Hi All, We''re told that in a group of children, the average (arithmetic mean) weight of the boys is 60 pounds, the average weight of the girls is 48 pounds and the average weight of ALL of the children in the group is 50 pounds. We''re asked for the ratio of the number of boys to the number of ...”
March 20, 2019
GMATGuruNY posted a reply to Reiko drove from point A to point B at a constant speed, and in the Data Sufficiency forum
“Test the THRESHOLD. Since we want to know whether the speed from A to B is greater than 40mph, the threshold here is 40mph. Statement 1: Reiko''s average speed for the entire round trip, excluding the time spent at point B, was 80 miles per hour. Let the distance in each direction = 40 ...”
March 19, 2019
Brent@GMATPrepNow posted a reply to If the average (arithmetic mean) of five consecutive negativ in the Problem Solving forum
“Let x = the 1st (smallest integer) So, x+1 = the 2nd integer x+2 = the 3rd integer x+3 = the 4th integer x+4 = the 5th integer (greatest integer) What is the difference between the greatest and least of the five integers? Difference = ( x+4) - x = 4 Answer: A Cheers, Brent”
March 19, 2019
Brent@GMATPrepNow posted a reply to The number 1000 lies between two consecutive perfect squares in the Problem Solving forum
“Let''s examine some perfect squares that are close to 1000 30² = 900 31² = 961 32² = 1024 So, 1000 lies between 961 (aka 31²) and 1024 (aka 32²) 1000 is closer to 1024 (aka 32²) than to 961 Answer: D Cheers, Brent”
March 19, 2019
GMATGuruNY posted a reply to Danny spends $360 buying his favorite dolls. If he buy only in the Problem Solving forum “Since a small doll costs$1 less than a large doll, the answer choices imply the following options for the price of a small doll: 4 5 6.2 7 8 Given that all of the values in the prompt are INTEGERS, the price of a small doll is almost certain to be a factor of 360. Only the values in blue ...”
March 18, 2019
Brent@GMATPrepNow posted a reply to Danny spends $360 buying his favorite dolls. If he buy only in the Problem Solving forum “Let L = cost of 1 LARGE LemonHead doll So L-1 = cost of 1 SMALL LemonHead doll If he buys only small LemonHead dolls, which are$1 cheaper than the large LemonHead dolls, he could buy 5 more dolls than if he were to buy only large LemonHead dolls. Let''s first write a "word equation": ...”
March 18, 2019
GMATGuruNY posted a reply to Of the 25 cars sold at a car dealership, some had auto trans in the Data Sufficiency forum
“The following cases satisfy both statements: Case 1: 2 cars have neither 1 car has both antilock breaks and automatic transmission 22 cars have only automatic transmission. Case 2: 2 cars have neither 22 cars have both antilock breaks and automatic transmission 1 car has only automatic ...”
March 18, 2019
GMATGuruNY posted a reply to A box contains 3 red balls, 4 green balls, 5 yellow balls, 6 in the Problem Solving forum
“Determine the WORST-CASE-SCENARIO -- for each color of ball, the MAXIMUM number that can be removed WITHOUT removing 5 of the same color: 3 red 4 green 4 yellow 4 blue 4 white Sum = 3+4+4+4+4 = 19 Implication: It is possible to remove 19 balls without selecting 5 of the same color. ...”
March 18, 2019
GMATGuruNY posted a reply to To fill an order, a manufacturer had to produce 1000 tools in the Data Sufficiency forum
“Prompt: Total production = 1000n Statement 1: Total production for the first 5 days = 5*600 = 3000 Statement 2: Total production for the last 4 days = 4*1500 = 6000 Case 1: n=9, with no days between the first 5 days and the last 4 days Total production = 1000n = 1000*9 = 9000 Total ...”
March 17, 2019
GMATGuruNY posted a reply to What is the sum of all values of that satisfy the equation 4 in the Problem Solving forum
“For any quadratic in the form x² + bx + c = 0: Product of the roots = c Sum of the roots = -b Given equation: 4x² + 16 = 32x 4x² - 32x + 16 = 0 x² - 8x + 4 = 0 In the resulting quadratic, b=-8. Thus: Sum of the roots = -(-8) = 8. The correct answer is E.”
March 17, 2019
GMATGuruNY posted a reply to Set P {a, b, c, d, e, f, g} Set Q {a, b, c, d, e, f} in the Problem Solving forum
“One approach: Show that four of the five answers do NOT have to be true. P--> a=1, b=2, c=3, d=5, e=6, f=7, g=4 Range = 7-1 = 6, median = 4, mean = (1+2+3+5+6+7+4)/7 = 28/7 Q --> a=1, b=2, c=3, d=5, e=6, f=7 Range = 7-1 = 6, median = (3+5)/2 = 4, mean = (1+2+3+5+6+7)/6 = 24/6 = 4 ...”
March 17, 2019
Brent@GMATPrepNow posted a reply to Bea owns how many more CDs than Al owns? (1) If Bea gives 9 in the Data Sufficiency forum
“Let A = number of CDs Al owns Let B = number of CDs Bea owns Target question: What is the value of B - A? Statement 1: If Bea gives 9 of her CDs to Al, then Al will own twice as many CDs as Bea owns. We can create the equation: 2(B - 9) = A+9 Expand left side to get 2B - 18 = A+9 ...”
March 16, 2019
GMATGuruNY posted a reply to If n is a positive integer and r is the remainder when in the Data Sufficiency forum
“What is the remainder when (n+1)(n-1) is divided by 8? Statement 1: Since n is odd, both n-1 and n+1 are EVEN, implying that (n-1)(n+1) = the product of two consecutive even integers. Given any two consecutive even integers, one will be a multiple of 4, while the other will be an even ...”
March 16, 2019
GMATGuruNY posted a reply to The sum of the weekly salaries of 5 employees is $3,250. If in the Problem Solving forum “Since each salary increases by 10%, the sum increases by 10%. 10% of 3250 = 325. Average increase per employee = (total increase)/(number of employees) = 325/5 = 65. The correct answer is E.” March 16, 2019 Brent@GMATPrepNow posted a reply to How many different 3-digit numbers are greater than 299 and in the Problem Solving forum “Take the task of creating the 3-digit numbers and break it into stages. Stage 1: Select the first digit (hundreds digit) Since the first digit can be 3, 4, 5, 7 or 9, we can complete stage 1 in 5 ways Stage 2: Select the second digit (tens digit) Since the second digit can be 0, 2, 3, 4, ...” March 15, 2019 Rich.C@EMPOWERgmat.com posted a reply to A certain hotel has 1,400 single rooms and 420 double rooms. in the Problem Solving forum “Hi camitava, This is essentially a rate question. Here''s how to solve it: Single rooms take one person 15 minutes to clean and double rooms take one person 20 minutes to clean. 15 mins. = 1/4 hour 20 mins. = 1/3 hour With 1400 single rooms x 1/4 hour = 350 hours of total work for ...” March 15, 2019 Rich.C@EMPOWERgmat.com posted a reply to A cosmetics company would like to market a six-item gift in the Problem Solving forum “Hi All, We''re told that a cosmetics company would like to market a 6-item gift basket bundle from a set of 10 possible items, but 49 of the potential bundles have already been eliminated from consideration. We''re asked for the total number of potential bundles that are still being considered. ...” March 15, 2019 Rich.C@EMPOWERgmat.com posted a reply to What is the sum of the integers from 1 to 999, inclusive? A in the Problem Solving forum “Hi All, We''re asked for the sum of the integers from 1 to 999, inclusive. This question can be approached in a number of different ways, including by "bunching" The sum of 1 and 999 is 1,000 The sum of 2 and 998 is 1,000 The sum of 3 and 997 is 1,000 Etc. Using the numbers ...” March 15, 2019 Rich.C@EMPOWERgmat.com posted a reply to A basketball team’s current roster consists of g guards an in the Problem Solving forum “Hi All, We''re told that a basketball team’s current roster consists of G guards and F forwards - and 2 guards join and 1 forward leaves. We''re asked for the probability that a player chosen at random is a guard. This question can be approached in a couple of different ways, including by ...” March 15, 2019 GMATGuruNY posted a reply to A rectangle has sides x and y and diagonal z. What is the pe in the Data Sufficiency forum “Always look for special triangles such as 3-4-5 and 5-12-13. Statement 2: Case 1: https://i.postimg.cc/V0JX8Hqv/rectangle-with-x-y-and-z-1.png Case 2: https://i.postimg.cc/DWCWwPyX/rectangle-with-x-y-and-z-2.png Since each case will yield a different perimeter, INSUFFICIENT. Statement ...” March 15, 2019 Brent@GMATPrepNow posted a reply to The cost of delivery for an order of desk chairs was$10.00 in the Data Sufficiency forum
“Target question: Is n > 24? Given: The cost of delivery for an order of desk chairs was $10.00 for the 1st chair, and$1 for each additional chair in the order. The office manager placed an order for n desk chairs. Statement 1: The delivery cost for the order totaled more than $30.00 ...” March 15, 2019 Brent@GMATPrepNow posted a reply to What is the average (arithmetic mean) of eleven consecutive in the Data Sufficiency forum “There''s a nice rule that says, "In a set where the numbers are equally spaced, the mean will equal the median." Since the consecutive integers are equally-spaced, their mean and median will be equal. Target question: What is the average of eleven consecutive integers? ...” March 15, 2019 GMATGuruNY posted a reply to combinations in the Problem Solving forum “The portion in red is incorrect: it should be not 4C1 but 2C1. If we select two upper case letters from two sets of twins, we must then select one lower case letter from the OTHER TWO SETS OF TWINS, yielding only two options for the lower case letter. For example: If we select A and B for the two ...” March 15, 2019 Rich.C@EMPOWERgmat.com posted a reply to After multiplying a positive integer A, which has n digits, in the Problem Solving forum “Hi Gmat_mission, We''re told that after multiplying a positive integer A (which has N digits) by (N+2), we get a number with (N+1) digits, all of whose DIGITS are (N+1). We''re asked for the number of possible values of A that ''fit'' this description. To start, this question certainly ...” March 15, 2019 Rich.C@EMPOWERgmat.com posted a reply to At a certain supplier, a machine of type A costs$20,000 and in the Problem Solving forum
“Hi All, This question is really just about basic arithmetic and staying organized. Based on the information in the prompt, there are two ''total costs'' that we have to calculate... Total cost of purchasing 2 Type A machines = Base Price = (2)($20,000) =$40,000 The 20% down payment = ...”
March 15, 2019
Rich.C@EMPOWERgmat.com posted a reply to In an office of eleven people, everyone but Lauren each in the Problem Solving forum
“Hi All, We''re told that in an office of 11 people, everyone but Lauren each contributed D dollars to buy her a surprise gift for her birthday, but the gift cost a total of G dollars, which was an amount that was less than the total collected. We''re asked - if each member who donated is to ...”
March 15, 2019
Brent@GMATPrepNow posted a reply to If 320 people attended the wedding and 200 attendees drank in the Data Sufficiency forum
“This question is somewhat ambiguous, since it''s hard to say whether "nondrinkers" in statement 1 refers to people who drank neither beer nor wine, or did not drink beer. I''m assuming that it means to not drink beer, so I''ve add that to the question below. One approach is to use ...”
March 14, 2019
Brent@GMATPrepNow posted a reply to Set X consists of different positive numbers arranged in in the Data Sufficiency forum
“Target question: What is the arithmetic mean of set X? Given: Set X consists of different positive numbers arranged in ascending order: K, L, M, 5, 7. K, L and M are consecutive integers This means that EITHER K, L, M = 1, 2, 3 respectively, OR K, L, M = 2, 3, 4 respectively Head straight ...”
March 14, 2019
GMATGuruNY posted a reply to If N is a positive two-digit integer, is N+1 prime? in the Data Sufficiency forum
“Good catch. In my solution, the lone exception (N=29) is now noted.”
March 14, 2019
GMATGuruNY posted a reply to If N is a positive two-digit integer, is N+1 prime? in the Data Sufficiency forum
“Statement 1: Any integer whose digits sum to a multiple of 3 must itself be a multiple of 3. Since N has a digit sum of 11, N+1 must have a digit sum of 12. One exception: If N=29, then N+1 = 30, which has a digit sum of 3. Since the digit sum of N+1 must be a multiple of 3 -- either 12 or 3 -- ...”
March 14, 2019
GMATGuruNY posted a reply to If √x+√y=7 and √x-√y=5, what is the value of xy? in the Problem Solving forum
“Adding the two equations, we get: 2√x = 12 √x = 6 x = 36 Substituting √x = 6 into √x+√y=7, we get: 6 + √y = 7 √y = 1 y = 1 Thus: xy = 36*1 = 36 The correct answer is C.”
March 14, 2019
GMATGuruNY posted a reply to If f(x)=ax^2+bx+c, where a, b and c are integers, is b=0? in the Data Sufficiency forum
“Statement 1: Since (49, 0) and (-49, 0) are both solutions, the quadratic must be as follows: f(x) = (x-49)(x+49) = x² - 49² In the resulting quadratic, b=0. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: If x-49 is a factor of the equation, then f(49) = 0. Case ...”
March 14, 2019
GMATGuruNY posted a reply to Ashley and Vinnie work on a sales staff with 8 other in the Problem Solving forum
“From the 10 people, 5 will be selected. Thus, P(Ashley is selected) = 5/10. From the 9 remaining people, 4 will be selected. Thus, P(Vinnie is selected) = 4/9. To combine these probabilities, we multiply: 5/10 * 4/9 = 2/9. The correct answer is C. Similar problem: ...”
March 14, 2019
Brent@GMATPrepNow posted a reply to combinations in the Problem Solving forum
“Sure thing. Number of outcomes that OBEY the restriction = (total # of outcomes that IGNORE the restriction) - (# of outcomes that BREAK the restriction) total # of outcomes that IGNORE the restriction Select any 3 people from the 8 people We can do this in 8C3 ways (= 56 ways) # of ...”
March 13, 2019
GMATGuruNY posted a reply to A cosmetics company would like to market a six-item gift in the Problem Solving forum
“From 10 items, the number of ways to choose a bundle of 6 = 10C6 = (10*9*8*7*6*5)/(6*5*4*3*2*1) = 210. Subtracting the 49 bundles already eliminated from consideration, we get: 210-49 = 161. The correct answer is B.”
March 13, 2019
GMATGuruNY posted a reply to Set M is composed of the positive even integers up to 100. in the Problem Solving forum
“For any EVENLY SPACED SET: Count = (biggest - smallest)/(increment) + 1. Average = (biggest + smallest)/2. Sum = (count)(average). The INCREMENT is the difference between successive values. Even integers between 2 and 100, inclusive: Here, the integers are EVEN, so the increment = 2. Count ...”
March 13, 2019
Brent@GMATPrepNow posted a reply to If when x is divided by z, the result is y remainder q, then in the Problem Solving forum
“When it comes to remainders, there''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 divided by 5 equals 3 with remainder 2, then we can write 17 = (5)(3) + 2 Likewise, since 53 divided by 10 equals 5 with remainder 3, then we ...”
March 13, 2019
Brent@GMATPrepNow posted a reply to If $5,000 invested for one year at p percent simple annual i in the Data Sufficiency forum “The great thing about DS questions is that we aren''t required to perform calculations if we know that we COULD perform those calculations. Here''s what I mean: Target question: What amount must be invested at k percent simple annual interest for one year to yield the same amount of dollars ? ...” March 13, 2019 Brent@GMATPrepNow posted a reply to If xyz ≠ 0, is x^3y^4z^5 > 0? in the Data Sufficiency forum “ Given: xyz ≠ 0 Target question: Is x³y⁴z⁵ > 0? This is a great candidate for rephrasing the target question. Since we know that x² must be POSITIVE, we can safely take the inequality x³y⁴z⁵ > 0 and divide both sides by x² to get: xy⁴z⁵ > 0 Similarly, since ...” March 13, 2019 Brent@GMATPrepNow posted a reply to Set M is composed of the positive even integers up to 100. in the Problem Solving forum “Set M is composed of the positive even integers up to 100. Set M = {2, 4, 6, 8, . . . . 96, 98, 100} Set N is composed of the odd integers from –1 to 99 Set N = {-1, 1, 3, 5, . . . 95, 97, 99} What is the value of (the sum of Set M) – (the sum of Set N)? SUM of set M = 2 + 4 + 6 + 8 + ...” March 13, 2019 Brent@GMATPrepNow posted a reply to A certain ball was dropped from a window 8 meters above a in the Problem Solving forum “Drop 8 meters Rise 4 meters Drop 4 meters Rise 2 meters Drop 2 meters Rise 1 meters (DONE!) 8 + 4 + 4 + 2 + 2 + 1 = 21 meters Answer: A Cheers, Brent” March 13, 2019 GMATGuruNY posted a reply to A set of 51 different integers has a median of 30 and a in the Problem Solving forum “Range = biggest - smallest Smallest = biggest - range Since the range = 60, we get: Smallest = biggest - 60 To minimize the smallest integer, we must minimize the biggest integer. Since the median of the 51 distinct integers = 30, there must be 25 integers above 30, with the other 25 ...” March 13, 2019 Brent@GMATPrepNow posted a reply to A certain hotel has 1,400 single rooms and 420 double rooms. in the Problem Solving forum “The hotel has 1,400 single rooms, and one person can clean a single room every 15 minutes So, one person can clean 4 single rooms in ONE HOUR In other words, it takes 1 WORKER HOUR to clean 4 single rooms 1400/4 = 350 So, it takes 350 WORKER HOURS to clean 1400 rooms The hotel has 420 ...” March 13, 2019 Brent@GMATPrepNow posted a reply to The number of candidates rejected in a certain admission pro in the Problem Solving forum “The number of candidates rejected in a certain admission process was four times GREATER than the number of candidates accepted. Let x = the number of candidates accepted So, x + 4x = the number of candidates rejected In other words, 5x = the number of candidates rejected So, 6x = TOTAL number ...” March 13, 2019 GMATGuruNY posted a reply to What is the sum of the integers from 1 to 999, inclusive? A in the Problem Solving forum “For any set of consecutive integers: Count = biggest - smallest + 1. Average = (biggest + smallest)/2. Sum = (count)(average). In the set above: Count = 999 - 1 + 1 = 999. Average = (999 + 1)/2 = 500. Sum = (999)(500) = (1000-1)(500) = 500000-500 = 499500. The correct answer is B.” March 13, 2019 GMATGuruNY posted a reply to Peter and Tom shared the driving on a certain trip. If Peter in the Problem Solving forum “Let the time for each driver = 1 hour. Let the total distance = 5 miles, implying that Peter''s distance = (2/5)(5) = 2 miles and that Tom''s distance = 5-2 = 3 miles. Since Peter drives 2 miles in 1 hour, Peter''s rate = 2 mph. Since Tom drives 3 miles in 1 hour, Tom''s rate = 3 mph. Thus: ...” March 13, 2019 Rich.C@EMPOWERgmat.com posted a reply to A student worked 20 days. For each of the amount shown in th in the Problem Solving forum “Hi All, We''re told that a student worked 20 days - and the given table shows the number of days that the student earned each of 5 possible amounts of money. We''re asked for the MEDIAN amount of money earned per day for those 20 days. Since there are 20 total days, the MEDIAN will be the ...” March 12, 2019 Rich.C@EMPOWERgmat.com posted a reply to In a group of 24 musicians, some are pianists and the rest a in the Problem Solving forum “Hi All, We''re told that in a group of 24 musicians, some are pianists and the rest are violinists and exactly 1/2 of the pianists and exactly 2/3 of the violinists belong to a union. We''re asked for the LEAST possible number of union members in the group. This question can be approached in a ...” March 12, 2019 Brent@GMATPrepNow posted a reply to In a group of 24 musicians, some are pianists and the rest a in the Problem Solving forum “In a group of 24 musicians, some are pianists and the rest are violinists. Let x = number of pianists So, 24-x = number of violinists Exactly 1/2 of the pianists and exactly 2/3 of the violinists belong to a union. So, the number of pianists in the union = x/2 And the number of violinists in ...” March 12, 2019 GMATGuruNY posted a reply to Which of the following could be the number of diagonals of a in the Problem Solving forum “To form a diagonal, we must choose 2 vertices. But any pair of vertices that forms a side of the polygon cannot serve to form a diagonal. Thus: Number of diagonals = (number of ways to choose 2 vertices) - (number of sides of the polygon) When the prompt includes the phrase which of the ...” March 12, 2019 GMATGuruNY posted a reply to Alice, Bob, Cindy, Darren, Eddie, Fabian sit on six chairs a in the Problem Solving forum “To count circular arrangements: 1. Place someone in the circle 2. Count the number of ways to arrange the REMAINING people Once Alice has been placed in the circle: Number of options for Bob = 1. (Must be in the seat opposite Alice) Number of options for Cindy = 4. (Any of the 4 remaining ...” March 12, 2019 GMATGuruNY posted a reply to If x and y are positive integers, x/y=? in the Data Sufficiency forum “Statement 1: Case 1: x=2 and y=1, with the result that 2^(x+y) * 3^(xy) = 2³3² = 72 In this case, x/y = 2/1 = 2. Case 2: x=1 and y=2, with the result that 2^(x+y) * 3^(xy) = 2³3² = 72 In this case, x/y = 1/2 = 1/2. Since x/y can be different values, INSUFFICIENT. Statement 2: Here, x=2 ...” March 12, 2019 GMATGuruNY posted a reply to Roman City in the Critical Reasoning forum “E: mosaic designs with which artisans who lived in various parts of the Roman Empire were familiar. Here, the two blue portions constitute an adjective serving to modify designs. Question: What KIND of designs? Answer: Designs WITH WHICH ARTISANS WERE FAMILIAR. Put another way: Artisans were ...” March 11, 2019 Rich.C@EMPOWERgmat.com posted a reply to If a certain reel of film runs at 5/6 of a frame per second, in the Problem Solving forum “Hi All, We''re told that a certain reel of film runs at 5/6 of a frame per second. We''re asked how long it will take to run 2580 frames of the film. While this question involves some ''ugly'' numbers, the answer choices are sufficiently ''spread out'' that you can use estimation to get the ...” March 11, 2019 Rich.C@EMPOWERgmat.com posted a reply to Five friends play blackjack in Las Vegas and lose an average in the Problem Solving forum “Hi All, We''re told that 5 friends play blackjack in Las Vegas and lose an AVERAGE of$100 each - with the losses of two of the friends totaling $380. We''re asked for the AVERAGE loss of the other 3 friends. This question is a standard Average Formula question and requires just a bit or ...” March 11, 2019 GMATGuruNY posted a reply to Carmen currently works 30 hours per week at her part-time jo in the Data Sufficiency forum “Rate and time have a RECIPROCAL relationship. If the hourly rate DOUBLES, then the same income will be yielded in 1/2 the total time. Statement 1: Actual hourly rate = 225/30 =$7.50, implying that an additional $1.50 per hour will increase the hourly rate to$9. (increased hourly ...”
March 11, 2019
Rich.C@EMPOWERgmat.com posted a reply to The R students in a class agree to contribute equally to buy in the Problem Solving forum
“Hi All, While this question is wordy, and will require some note-taking, it can be solved by TESTing VALUES. Let''s TEST... R = 5 students Y = 50 dollars X = 3 fail to pay So the ''story'' is that 5 students agree to pay an equal amount for a $50 present (that''s$10 per student). We''re ...”
March 11, 2019
Rich.C@EMPOWERgmat.com posted a reply to A city council will select 2 of 9 available firefighters and in the Problem Solving forum
“Hi All, We''re told that a city council will select 2 of 9 available firefighters and 1 of 6 available police officers to serve on an advisory panel. We''re asked for the number of different groups of 3 people that could serve on the panel. This question is essentially a Combination Formula ...”
March 11, 2019
Rich.C@EMPOWERgmat.com posted a reply to Ramon wants to cut a rectangular board into identical square in the Problem Solving forum
“Hi All, We''re asked to find the minimum number of identical SQUARES that be cut from an 18 in. x 30 in. board without ''wasting'' any of the space. To accomplish this, we need to find a square whose dimensions will evenly divide into both 18 and 30; to find the LEAST number of squares, we''ll ...”
March 11, 2019
Brent@GMATPrepNow posted a reply to Carmen currently works 30 hours per week at her part-time jo in the Data Sufficiency forum
“ Given: Carmen currently works 30 hours per week Target question: If Carmen''s gross hourly wage were to increase by 1.50, how many fewer hours could she work per week and still earn the same gross weekly pay as before the increase? This is a good candidate for rephrasing the target ...” March 11, 2019 Brent@GMATPrepNow posted a reply to W, X, Y and Z are four different positive integers. When X in the Problem Solving forum “ Given: When X is divided by Y, the quotient is Z and the remainder is W. ------ASIDE------- There''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 divided by 5 equals 3 with remainder 2, then we can write 17 = (5)(3) + 2 ...” March 11, 2019 Brent@GMATPrepNow posted a reply to What is the hundredths digit of the decimal z? in the Data Sufficiency forum “Target question: What is the hundredths digit of the decimal z? Statement 1: The tenths digit of 100z is 2 Notice what happens when we take a decimal like 0.123456 and multiply it by 100. We get 12.345 (the tenths digit is 3) In the original decimal, the 3 was in the thousandths place. ...” March 10, 2019 Brent@GMATPrepNow posted a new topic called W, X, Y and Z are four different positive integers. When X in the Problem Solving forum “W, X, Y and Z are four different positive integers. When X is divided by Y, the quotient is Z and the remainder is W. If W = X – 7, what is the sum of all possible values of W? A) 19 B) 20 C) 21 D) 22 E) 23 Source: www.gmatprepnow.com Difficulty level: 650 - 700” March 10, 2019 Brent@GMATPrepNow posted a reply to If 4x − 3y = 13 and 5x + 2y = − 1, then x = in the Problem Solving forum “GIVEN: 4x − 3y = 13 5x + 2y = − 1 Take the TOP equation and multiply both sides by 2 Take the BOTTOM equation and multiply both sides by 3 We get: 8x - 6y = 26 15x + 6y = -3 ADD the two equations to get: 23x = 23 Solve: x = 23/23 = 1 Answer: C Cheers, Brent” March 10, 2019 GMATGuruNY posted a reply to schistosomiasis and malaria. in the Critical Reasoning forum “M --> more than 50% of all disease cases over the past 5 years S --> 40% of all disease cases 5 years ago, 30% of all disease cases now For each answer choice: Try to devise a case that aligns with the information in the passage but CONTRADICTS the answer choice, thus proving that the ...” March 9, 2019 GMATGuruNY posted a reply to Verbal Review 18 : Kudzu, an Asian vine in the Sentence Correction forum “Generally, COMMA + SINCE after a clause serves to express a CAUSAL relationship. An OA in GMATPrep: Prospecting for gold was a relatively easy task, since erosion put gold literally within reach of anybody with a pan. Here, the clause in blue serves to express what CAUSED prospecting to be a ...” March 9, 2019 GMATGuruNY posted a reply to If p is a positive integer, is 2p + 1 prime? in the Data Sufficiency forum “Statements combined: Case 1: p=11 --> p is prime, but its units digits is not prime In this case, 2p+1 = 2*11 + 1 = 23. Since 23 is prime, the answer to the question stem is YES. Case 2: p=19 --> p is prime, but its units digit is not prime In this case, 2p+1 = 2*19 + 1 = 39. Since 39 ...” March 9, 2019 GMATGuruNY posted a reply to If a certain reel of film runs at 5/6 of a frame per second, in the Problem Solving forum “2580 frames * (1 second)/(5/6 frame per second) * (1 minute)/(60 seconds) = 2580/50 = a little over 50 minutes. The correct answer is B.” March 9, 2019 Brent@GMATPrepNow posted a reply to W, X, Y and Z are four different positive integers. in the Data Sufficiency forum “Target question: What is the value of Z? Given: When X is divided by Y, the quotient is Z and the remainder is W. ------ASIDE------- There''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 divided by 5 equals 3 with ...” March 8, 2019 GMATGuruNY posted a reply to When positive integer x is divided by positive interger y, in the Problem Solving forum “When one positive integer is divided by another, we typically represent what is left over as a REMAINDER or as a DECIMAL. There is a relationship between the two representations: Remainder/Divisor = Decimal. When 5 is divided by 2: Remainder representation: 5/2 = 2 R1 Decimal ...” March 8, 2019 GMATGuruNY posted a reply to The R students in a class agree to contribute equally to buy in the Problem Solving forum “Let y=10 and R=10 students, with the result that the original share per student = ($10)/(10 students) =$1. Let x=9, implying that the number of students decreases by 9 to 1. New share per student = ($10)/(1 student) =$10. Increase in share per student = 10-1 = $9. The correct answer must ...” March 8, 2019 Brent@GMATPrepNow posted a reply to OG 2017 Ratio Question in the Data Sufficiency forum “Target question: What is the total number of articles of clothing in the closet? Given: The ratio of the number of shirts to the number of dresses to the number of jackets in the closet is 9:4:5, respectively. If shirts : dresses : jackets = 9 : 4 : 5, then there are infinitely many ...” March 7, 2019 Brent@GMATPrepNow posted a new topic called W, X, Y and Z are four different positive integers. in the Data Sufficiency forum “W, X, Y and Z are four different positive integers. When X is divided by Y, the quotient is Z and the remainder is W. What is the value of Z? 1) W = X – 4 2) W + Z = 4 Difficulty level: 650 – 700 Source: www.gmatprepnow.com” March 7, 2019 Brent@GMATPrepNow posted a reply to 60 DAY STUDY GUIDE ENQUIRY in the Ask a GMAT Prep Now representative forum “Sorry, but there are no plans to update the 60-day guide in the near future. Cheers, Brent” March 7, 2019 GMATGuruNY posted a reply to Is the average (arithmetic mean) of x, y, and z equal to the in the Data Sufficiency forum “Statement 1: In other words, y is HALFWAY BETWEEN x and z, implying that x, y and z are EVENLY SPACED. For any evenly spaced set, the average = the median. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: x+z = 2y (x+z)/2 = y Implication: y is the average of x and z ...” March 7, 2019 GMATGuruNY posted a reply to What is the remainder when -12 is divided by -5? in the Problem Solving forum “This problem is not relevant to the GMAT. On the GMAT, problems involving remainders are constrained to POSITIVE INTEGERS. From the Math Review in the OG: If x and y are positive integers, there exist unique integers q and r, called the quotient and remainder, respectively, such that y = xq + r ...” March 7, 2019 Brent@GMATPrepNow posted a reply to What is the sum of all of the integers in the chart above? in the Problem Solving forum “Always check the answer choices BEFORE solving the question!! Since the answer choices are nicely spread apart, we can be quite aggressive in our estimation Let''s add the 5 numbers in each COLUMN COLUMN 1: Sum ≈500 COLUMN 2: Sum ≈-1000 COLUMN 3: Sum ≈1500 COLUMN 4: Sum ≈-2000 ...” March 6, 2019 Brent@GMATPrepNow posted a reply to If 0.02 < x < 0.04 and 100 < y < 250, which of t in the Problem Solving forum “We can use a nice (and often tested) fraction property that says: (a - b)/c = a/c - bc So, (y-x)/(xy) = y/xy - x/xy = 1/x - 1/y That''s better! So, we''re now looking for a possible value of 1/x - 1/y Let''s look at some EXTREME values. We can MAXIMIZE the value of 1/x - 1/y by MAXIMIZING ...” March 6, 2019 Brent@GMATPrepNow posted a reply to For every even positive integer m, f(m) represents the in the Problem Solving forum “f(24) = 2 x 4 x 6 x 8 x 10 x 12 x 14 x 16 x 18 x 20 x 22 x 24 Rewrite as prime factorization: f(24) = 2 x (2)(2) x (2)(3) x (2)(2)(2) x (2)(5) x (2)(2)(3) x (2)(7) x (2)(2)(2)(2) x (2)(3)(3) x (2)(2)(5) x (2)(11) x (2)(2)(2)(3) Answer: E ASIDE: As you can see from the answer choice, I ...” March 6, 2019 Brent@GMATPrepNow posted a reply to Is xy>3? in the Data Sufficiency forum “Target question: Is xy > 3 ? Statement 1: (7^x) > 729 Since there''s no information about y, we cannot answer the target question with certainty. Statement 1 is NOT SUFFICIENT Statement 2: (9^y) = 7 Since there''s no information about x, we cannot answer the target question with ...” March 5, 2019 GMATGuruNY posted a reply to A triangle of area 30 is formed by the line x/c + y/(c+7) - in the Problem Solving forum “Given that the area and the answer choices are all integers, the triangle is probably a Pythagorean Triple. The only Pythagorean Triple with an area of 30 is 5-12-13. In the given equation, test c=5, with the result that c+7 = 12: x/5 + y/12 - 1 = 0 If x=0, then y=12, implying a y-intercept ...” March 5, 2019 Brent@GMATPrepNow posted a reply to x is the product of all even numbers from 2 to 50, inclusive in the Problem Solving forum “Here''s a very similar (official) question to practice with: https://www.beatthegmat.com/arthemetic-question-on-factors-and-prime-numbers-t275643.html Cheers, Brent” March 5, 2019 GMATGuruNY posted a reply to Joey works at a clothing store and receives an employee in the Problem Solving forum “Since the discount = 10% = 1/10, and the resulting discount price is an integer value, the regular price must be a dollar value that is a multiple of 10. The correct answer is E.” March 5, 2019 Brent@GMATPrepNow posted a reply to Joey works at a clothing store and receives an employee in the Problem Solving forum “Let R = REGULAR price of the item Joey and receives an employee discount of 10 percent off the regular price of any item. So, Joey pays 90% of the REGULAR price. In other words, 0.9R = the DISCOUNT price that Joey actually pays What is the regular price of an item that Joey purchases for ...” March 5, 2019 GMATGuruNY posted a reply to When 32 is divided by k, the remainder is k-3. What is the in the Data Sufficiency forum “Dividing 32 by k leaves a remainder of k-3. In other words, 32 is equal to k-3 more than a multiple of k: 32 = ak + (k-3), where a is a nonnegative integer and k is an integer such that k≥3. Simplifying 32 = ak + (k-3), we get: 35 = ak + k 35 = k(a+1) The resulting equation implies that ...” March 5, 2019 GMATGuruNY posted a reply to If x and y are positive integers and (x-y)^2+y^2=25, which o in the Problem Solving forum “Identify two perfect squares that sum to 25: 1, 4, 9, 16... The two values in blue sum to 25. If y=3 and x=7, then (x-y)² = (7-3)² = 16 and y² = 9, with the result that (x-y)² + y² = 25. The correct answer is B.” March 5, 2019 Brent@GMATPrepNow posted a reply to In how many ways can 16 different gits be divided among four in the Problem Solving forum “Let''s say the children are named A, B, C, and D Stage 1: Select 4 gifts to give to child A Since the order in which we select the 4 gifts does not matter, we can use combinations. We can select 4 gifts from 16 gifts in 16C4 ways (= 16!/(4!)(12!)) So, we can complete stage 1 in ...” March 4, 2019 Brent@GMATPrepNow posted a reply to The positive two-digit integers x and y have the same digits in the Problem Solving forum “Another approach is to test some values for x and y that satisfy the given information. Positive two-digit integers x and y have the same digits, but in reverse order So, it COULD be the case that x = 12 and y = 21 Which of the following must be a factor of x + y? x + y = 12 + 21 = 33 ...” March 3, 2019 GMATGuruNY posted a reply to OG Before 1988, insurance companies in California in the Sentence Correction forum “Generally, COMMA + VERBing serves to modify the nearest preceding action and the agent of this action. Given this rule, I received a PM requesting that I justify the usage of COMMA + needing in the OA: Insurance companies in California were free to charge whatever rates the market would bear, ...” March 3, 2019 Rich.C@EMPOWERgmat.com posted a reply to Working continuously 24 hours a day, a factory bottles Soda in the Problem Solving forum “Hi All, We''re told that working continuously 24 hours a day, a factory bottles Soda Q at a rate of 500 liters per second and Soda V at a rate of 300 liters per second and that TWICE as many bottles of Soda V as of Soda Q are filled at the factory each day. We''re asked for the ratio of the ...” March 2, 2019 Rich.C@EMPOWERgmat.com posted a reply to Two hoses are pouring water into an empty pool. Hose 1 alone in the Problem Solving forum “Hi All, This question is a variation of a ''Work Formula'' question (it involves 2 ''entities'' working on the same task together), so we can use the Work Formula to solve it. Work = (A)(B)/(A+B) where A and B are the individual times that it takes the 2 entities to complete the task on their ...” March 2, 2019 Rich.C@EMPOWERgmat.com posted a reply to Range Problem.,... in the Problem Solving forum “Hi All, We''re told that Set X consists of PRIME numbers {3, 11, 7, K, 17, 19}, the integer Y represents the PRODUCT of all elements in Set X and 11Y is an EVEN number. We''re asked for the RANGE of Set X. This question is based on several Number Property rules - and doesn''t actually require ...” March 2, 2019 Rich.C@EMPOWERgmat.com posted a reply to In how many ways can the letters D, I, G, I, T be arranged in the Problem Solving forum “Hi All, We''re asked to find the number of ways that the letters D, I, G, I, T be arranged so that the two I''s are NOT next to each other. Since the two "I"s cannot be side-by-side, there are a limited number of ways to arrange the 5 letters. As such, with a little permutation math ...” March 2, 2019 Brent@GMATPrepNow posted a reply to Median of set T in the Problem Solving forum “If we have a set of y INTEGERS, there are two possible cases when it comes to the MEDIAN. Case a: y is an ODD number, in which case the MEDIAN equals the one middle integer (when all of the integers are arranged in ascending order). In this case, the median must be an integer. Case b: y is an ...” March 2, 2019 GMATGuruNY posted a reply to In a certain school, there are 160 boys and 240 girls. If 15 in the Problem Solving forum “Left-handed boys = 15% of 160 = 24. Left-handed girls = 25% of 240 = 60. (total left-handed)/(total students) = (24+60)/(160+240) = 84/400 = 21/100 = 21%. The correct answer is C.” March 2, 2019 GMATGuruNY posted a reply to If $$2^{4x}=3,600$$, what is the value of $$(2^{(1-x)})^2$$? in the Problem Solving forum “$$(2^{(1-x)})^2$$ = $$2^{2-2x}$$ = $$2^2/2^{2x}$$ = $$4/2^{2x}$$ We need to know the value of $$2^{2x}$$: $$2^{4x}=3,600$$ $$(2^{2x})^2=3,600$$ $$2^{2x}= 60$$ Substituting $$2^{2x}= 60$$ into $$4/2^{2x}$$, we get: 4/60 = 1/15 The correct answer is B.” March 2, 2019 GMATGuruNY posted a reply to Car B starts at point X and moves clockwise around a circula in the Problem Solving forum “π ≈ 3. Car B is traveling for more than 10 hours, so answer choices D and E are too small, and A is unlikely. The correct answer is either B or C. Circumference of track = 20π ≈ 60 miles. In 10 hours, distance for B = 2*10 = 20 miles. 60-20 = 40 miles between A and B. A and B now ...” March 2, 2019 GMATGuruNY posted a reply to Which of following satisfies the inequality (2x-49)(x^2+6x+1 in the Problem Solving forum “The two factors must have DIFFERENT SIGNS. Each of the answer choices will yield a positive value for x² + 6x + 10. Thus, the correct answer must yield a negative value for 2x-49. Only A is viable: (2*24) - 49 = -1. The correct answer is A.” March 1, 2019 GMATGuruNY posted a reply to Andrew bought pizzas for his swim team. Pepperoni pizzas in the Problem Solving forum “Posted and answered about a week ago: https://www.beatthegmat.com/andrew-bought-pizzas-for-his-swim-team-pepperoni-pizzas-cos-t306615.html#827261” March 1, 2019 GMATGuruNY posted a reply to The three squares above share vertex A with AF = FE and AE = in the Problem Solving forum “Let AF=FE=1, with the result that AE=ED=2: https://i.postimg.cc/2qmj2KbL/probability-and-three-squares.png As the figure illustrates: shaded region = 1+1+1 = 3 ABCD = 4*4 = 16 shaded/ABCD = 3/16 The correct answer is D.” March 1, 2019 Rich.C@EMPOWERgmat.com posted a reply to The product of the digits of the four-digit number h is 36. in the Problem Solving forum “Hi All, We''re told that the product of the digits of the four-digit number H is 36 and no two digits of H are identical. We''re asked for the number of different possible values of H. While this question might seem complex, most of the work is based on basic Arithmetic (and some Permutation ...” March 1, 2019 Rich.C@EMPOWERgmat.com posted a reply to A motorcycle travels at a speed of x kilometers per p hours. in the Problem Solving forum “Hi All, We''re told that a motorcycle travels at a speed of X KILOMETERS per P HOURS. We''re asked for the number of METERS it will travel in S SECONDS, in terms of S, P and X. (xps ≠ 0; 1 kilometer = 1000 meters). This question can be solved in a number of different ways, including by TESTing ...” March 1, 2019 Rich.C@EMPOWERgmat.com posted a reply to All assets in Karina's investment portfolio are divided in the Problem Solving forum “Hi All, We''re told that all assets in Karina''s investment portfolio are divided between an IRA, 401k, and two separate taxable accounts and that NO two accounts have the SAME amount of money and all four have at least SOME money in them. If each account has a whole-number percent of Karina''s ...” March 1, 2019 Rich.C@EMPOWERgmat.com posted a reply to Vivian drives to her sister’s house and back. She takes th in the Problem Solving forum “Hi All, We''re told that Vivian drives to her sister''s house and back. She takes the exact same route both ways; on the trip out she drives an average speed of 50 miles per hour and on the trip back she drives an average speed of 70 miles per hour. We''re asked for her approximate average speed ...” March 1, 2019 Rich.C@EMPOWERgmat.com posted a reply to Tips for improving GMAT from 500-700 in the GMAT Strategy forum “Hi Rahufalb, To start, the only practical way to properly measure your overall Test-taking skills during the course of your studies is to take a FULL-LENGTH CAT under realistic conditions (meaning that you should take a FULL CAT - with the Essay and IR sections, in a location that is NOT your ...” March 1, 2019 Brent@GMATPrepNow posted a reply to Two positive numbers differ by 12 and their reciprocals in the Problem Solving forum “Two positive numbers differ by 12 Let x = the smaller number So x + 12 = the larger number NOTE: our goal is to find the value of x(x + 12) Their reciprocals differ by 4/5 We get: 1/x - 1/(x+12) = 4/5 Multiply both sides by x to get: 1 - x/(x + 12) = 4x/5 Multiply both sides by 5 to get: 5 ...” February 28, 2019 Brent@GMATPrepNow posted a reply to In a town of 8,000 residents, 65 percent of all residents in the Problem Solving forum “Another approach is to use the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it (aka overlapping sets questions). Here, we have a population of residents, and the two characteristics are: ...” February 28, 2019 Brent@GMATPrepNow posted a reply to Working simultaneously and independently at an identical con in the Problem Solving forum “Let''s assign a nice value to x (a value that will work well with all of the numbers 3, 4 and 6. Let''s say x = 24 GIVEN: 4 machines make x units in 6 days This means 4 machines make 24 units in 6 days So, 4 machines make 4 units in 1 day So, 1 machine makes 1 unit in 1 day From here, ...” February 28, 2019 Brent@GMATPrepNow posted a reply to A certain club has 20 members. What is the ratio of the in the Problem Solving forum “5-member committees Since the order in which we select the committee members does not matter, we can use COMBINATIONS We can select 5 people from 20 people in 20C5 ways 20C5 = (20)(19)(18)(17)(16)/(5)(4)(3)(2)(1) 4-member committees Since the order in which we select the committee members ...” February 28, 2019 Brent@GMATPrepNow posted a reply to Train A and Train B began traveling towards each other from in the Problem Solving forum “This is a SHRINKING GAP question. Train A traveled at 35 miles per hour and Train B traveled at 25 miles per hour, 35 mph + 25 mph = 60 mph So, the gap CLOSES at a rate of 60 mph Train A and Train B began traveling towards each other from opposite ends of a 500-mile long track at 1:00 PM ...” February 28, 2019 GMATGuruNY posted a reply to Working simultaneously and independently at an identical con in the Problem Solving forum “Use the following equation: (machines)(time) / output = (machines)(time) / output In the equation above: Machines and time are INVERSELY PROPORTIONAL. As the number of machines increases, the amount of time required to produce the same output decreases. Machines and output are DIRECTLY ...” February 28, 2019 GMATGuruNY posted a reply to The restorative power of sleep is graphically approximated b in the Problem Solving forum “Multiplying the equation by -1, we get: y = x² - 16x - 36 y = (x-18)(x+2) The restorative power -- the value of y -- is equal to 0 when x=18 or x=-2. Since the time cannot be a negative value, only x = 18 hours is viable. The correct answer is E.” February 28, 2019 GMATGuruNY posted a reply to In June 1989, what was the ratio of the number of sales tran in the Data Sufficiency forum “What is (June X)/(June Y)? Statement 1: In June 1989, Salesperson X made 50 percent more sales transactions than Salesperson Y did in May 1989. (June X)/(May Y) = 150/100 = 3/2. INSUFFICIENT. Statement 2: In June 1989, Salesperson Y made 25 percent more sales transactions than in May ...” February 28, 2019 Brent@GMATPrepNow posted a reply to In 1990 the budgets for projects Q and V were$660,000 and in the Problem Solving forum
“One approach is to treat this is a rate question. In 1990 the GAP BETWEEN V''s budget and Q''s budget was $120,000 ($780,000 - $660,000 =$120,000) Each year, the budget for Q increased by $30,000 and the budget for V decreased by$10,000. In other words, the GAP BETWEEN the budgets ...”
February 28, 2019
GMATGuruNY posted a reply to How many whole numbers between 100 and 400, inclusive, conta in the Problem Solving forum
“(integers with the digit 2) = (all integers between 100 and 399, inclusive) - (integers without the digit 2) All integers between 100 and 399, inclusive: For any set of consecutive integers, count = biggest - smallest + 1. In this case: count = 399-100+1 = 300 Integers without the digit 2: ...”
February 27, 2019
GMATGuruNY posted a reply to A square playground has the same area as a rectangular in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent a side of the square. Since the dimension of the rectangular playground are INTEGER values, the correct answer is probably also an integer. When the correct answer is plugged in, the square and the rectangle will have the same area. D: 50, implying ...”
February 27, 2019
GMATGuruNY posted a reply to Two hoses are pouring water into an empty pool. Hose 1 alone in the Problem Solving forum
“Let the pool = 12 gallons. Since Hose 1 takes 6 hours to fill the 12-gallon pool, the rate for Hose 1 = w/t = 12/6 = 2 gallons per hour. Since Hose 2 takes 4 hours to fill the 12-gallon pool, the rate for Hose 2 = w/t = 12/4 = 3 gallons per hour. Since the combined rate for the two hoses = 2+3 = ...”
February 27, 2019
GMATGuruNY posted a reply to What is the value of a+b? in the Data Sufficiency forum
“Statements combined: Adding the two equations, we get: a² + b²+ 2ab - 2a - 2b = 63 (a+b)² - 2(a+b) = 63 (a+b)(a+b-2) = 63 Let x = a+b. Substituting x=a+b into (a+b)(a+b-2) = 63, we get: (x)(x-2) = 63 x² - 2x - 63 = 0 (x-9)(x+7) = 0 x=9 or x=-7 Since x=a+b, it is possible that ...”
February 26, 2019
GMATGuruNY posted a reply to On a Saturday night, each of the rooms at a certain motel in the Problem Solving forum
“If 10 rooms are rented for $40 instead of$60 -- a decrease of $20 per room -- the total decrease = 10*20 =$200. Since the value in blue constitutes a 25% reduction in the total rent, it must be equal to 1/4 of the total rent: 200 = (1/4)R 800 = R. The correct answer is B.”
February 26, 2019
Rich.C@EMPOWERgmat.com posted a reply to Materials for solving. in the GMAT Strategy forum
“Hi Zaidf1997, It sounds like you''re just beginning your studies. Have you done any studying so far or are you just beginning? If you are just starting out, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can take 2 for free at www.mba.com (and they come with some ...”
February 26, 2019
GMATGuruNY posted a reply to A manufacturer makes umbrellas at the cost of c dollars per in the Problem Solving forum
“How many umbrellas can it afford to sell at the below-cost rate of b dollars per umbrella and still make a 100% profit? If c=1 and r=2 -- implying that the cost per umbrella = $1 and that the retail price per umbrella =$2 -- then 100% profit will be yielded only if ALL of the umbrellas are sold at ...”
February 26, 2019
Brent@GMATPrepNow posted a reply to Is xy+zt+yz+tx positive? in the Data Sufficiency forum
“Target question: Is xy + zt + yz + tx positive? Statement 1: |x| = |y| = |z| = t Let''s TEST some values. There are several values of x, y, z and t that satisfy statement 1. Here are two: Case a: x = y = z = t = 1. In this case, xy + zt + yz + tx = (1)(1) + (1)(1) + (1)(1) + (1)(1) = 4. ...”
February 26, 2019
Brent@GMATPrepNow posted a reply to A manufacturer makes umbrellas at the cost of c dollars per in the Problem Solving forum
“This is a tough one to use the INPUT-OUTPUT approach, but here is goes: Let c = $2 (it cost$2 to make each umbrella) Let x = 10 (we make 10 umbrellas) Let r = $5 (the retail price is$5 per umbrella) Let b = $0 (the below-cost sale price is$0 per umbrella) So, the manufacturer made 10 ...”
February 26, 2019
GMATGuruNY posted a reply to On rainy mornings, mo drinks exactly N cups of hot chocolate in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the number of rainy days. When the correct answer is plugged in, the total number of cups = 26. B: 3 rainy days, implying 4 non-rainy days Since 5 cups of tea are consumed are on each of the 4 non-rainy days, the total number of tea cups = 5*4 = 20. ...”
February 26, 2019
GMATGuruNY posted a reply to It takes Carlos 9 minutes to drive from home to work at an in the Problem Solving forum
“(new rate)/(old rate) = (6 miles per hour)/(22 miles per hour) = 6/22 = 3/11. Rate and time have a RECIPROCAL relationship. Since the new rate is 3/11 of the old rate, the new time must be 11/3 of the old time: (11/3)(9 minutes) = 33 minutes. The correct answer is B.”
February 26, 2019
GMATGuruNY posted a reply to A is the set of 6-digit positive integers whose first three in the Problem Solving forum
“The GMAT is unlikely to test divisibility by 7. An integer of the form XYZXYZ must be divisible by 7, but this issue seems irrelevant to the GMAT. For this reason, I''ve replaced answer choice A with the value in red: To determine whether an integer is divisible by 11: 1. From the left to ...”
February 26, 2019
GMATGuruNY posted a reply to What is the difference between the areas of the squares ABCD in the Data Sufficiency forum
“Statement 1: Case 1: DC=10 and EC=6, with the result that CDE = (1/2)(10)(6) = 30 In this case, ABCD-EFGC = 10² - 6² = 100 - 36 = 64. Case 2: DE=20 and EC=3, with the result that CDE = (1/2)(20)(3) = 30 In this case, ABCD-EFGC = 20² - 3² = 400 - 9 = 391. Since ABCD-EFGC can be different ...”
February 25, 2019
GMATGuruNY posted a reply to How many positive two-digit numbers are odd, not divisible b in the Problem Solving forum
“For any set of consecutive integers: count = biggest - smallest + 1 Thus: Number of two-digit integers between 10 and 99, inclusive = 99-10+1 = 90. Of these 90 consecutive integers, 1 of every 3 will be a multiple of 3, implying that 2/3 will NOT be divisible by 3: (2/3)(90) = 60. Of these ...”
February 25, 2019
Brent@GMATPrepNow posted a reply to How many positive two-digit numbers are odd, not divisible b in the Problem Solving forum
“After about 30 seconds, I recognized that I couldn''t see a nice straightforward solution (one that doesn''t involve considering multiple cases), so I had 3 options: 1) Keep searching for a nice straightforward solution 2) Guess and move on 3) List the possible outcomes Since the answer ...”
February 25, 2019
Brent@GMATPrepNow posted a reply to Nine identical chips are numbered from 1 to 9 (one different in the Problem Solving forum
“ODDS: 1, 3, 5, 7, 9 EVENS: 2, 4, 6, 8 Take the task of removing the 9 chips and break it into stages. Stage 1: Select an ODD number to be the 1st selection There are 5 ODDs to choose from. So, we can complete stage 1 in 5 ways Stage 2: Select an EVEN number to be the 2nd selection ...”
February 25, 2019
Brent@GMATPrepNow posted a reply to All assets in Karina's investment portfolio are divided betw in the Problem Solving forum
“Let''s say Karina''s entire portfolio is worth $100 altogether. So, we want to divide this$100 into four integer amounts: w, x, y, z, where w < x < y < z, and we want to minimize the value of z In order to MINIMIZE the value of the z, we must MAXIMIZE the values of w, x, and y. Now ...”
February 25, 2019
Brent@GMATPrepNow posted a reply to Vivian drives to her sister’s house and back. She takes th in the Problem Solving forum
“One approach is to assign a "nice" value (one that works well with 50 mph and 70 mph) to the distance her sister''s house. So, let''s say the distance is 350 miles Average speed = (total distance traveled)/(total travel time) TOTAL distance = 350 miles + 350 miles = 700 miles ...”
February 25, 2019
GMATGuruNY posted a reply to 2016 OG CR 30 in the Critical Reasoning forum
“Why do people who do regular volunteer work live longer? The argument concludes that ENDORPHINS are the cause. One way to weaken this conclusion is to suggest an ALTERNATE CAUSE. D: People tend not to become involved in regular volunteer work unless they are healthy and energetic to begin with. ...”
February 25, 2019
GMATGuruNY posted a reply to Vivian drives to her sister’s house and back. She takes th in the Problem Solving forum
“When the SAME DISTANCE is traveled at two different speed, the average speed for the entire trip will be just a little less than the average of the two speeds. The reason: The trip at the lower speed takes longer than the trip at the higher speed. Since more time is spent at the lower speed, the ...”
February 25, 2019
GMATGuruNY posted a reply to Before January, the price of a dress was D and the price of in the Problem Solving forum
“Let H=100 and D=500. D increased by 40% = 500 + (40/100)(500) = 500+200 = 700. H increased by 50% = 100 + (50/100)(100) = 100+50 = 150. New sum = 700+150 = 850. Amount paid = new sum discounted by 30% = 850 - (30/100)(850) = 850-255 = 595. The question stem asks for the amount paid. The ...”
February 25, 2019
GMATGuruNY posted a reply to All assets in Karina's investment portfolio are divided betw in the Problem Solving forum
“To MINIMIZE the percent for the largest balance, MAXIMIZE the percents for the 3 smallest balances. We can PLUG IN THE ANSWERS, which represent the percent in the largest balance. When the correct answer is plugged in, the 4 percents will sum to 100%. Since the question stem asks for the smallest ...”
February 25, 2019
Rich.C@EMPOWERgmat.com posted a reply to Ten theater students are to begin work on a set for a in the Problem Solving forum
“Hi All, We''re told that 10 theater students are to begin work on a set for a musical. Working at a constant rate, they will finish the set in 60 days, but the director of the musical decides they need to finish in 50 days. We''re asked for the number of ADDITIONAL theater students we would ...”
February 24, 2019
Rich.C@EMPOWERgmat.com posted a reply to A circular lawn with a radius of 5 meters is surrounded by a in the Problem Solving forum
“Hi All, We''re told that a circular lawn with a radius of 5 meters is surrounded by a circular walkway that is 4 meters wide. We''re asked for the area of the walkway. This is an example of a ''punch out'' question - we need to find the area of the ENTIRE shape and then ''punch out'' the part ...”
February 24, 2019
Rich.C@EMPOWERgmat.com posted a reply to Kim has 40 percent more money than Sal and Sal has 20 in the Problem Solving forum
“Hi All, We''re told that Kim has 40 percent MORE money than Sal, Sal has 20 percent LESS money than Phil and Sal and Phil have a combined total of $1.80. We''re asked for the amount of money that Kim has. This question can be approached in a couple of different ways, including some brute-force ...” February 24, 2019 GMATGuruNY posted a reply to In a certain class, the ratio of girls to boys is 5:4. How m in the Data Sufficiency forum “g:b = 5:4 = 10:8 = 15:12 = 20:16 = 25:20... Statement 1: In other words, 4 boys are equal to 20% of the current number of boys, implying the blue ratio above, since 20% of 20 boys = 4 boys. In the blue ratio above, the number of girls = 25. SUFFICIENT. Statement 2: Test the smaller red ...” February 24, 2019 Brent@GMATPrepNow posted a reply to In a certain class, the ratio of girls to boys is 5:4. How m in the Data Sufficiency forum “ Given: In a certain class, the ratio of girls to boys is 5:4. Let G = number of girls in the class Let B = number of boys in the class We can write: G/B = 5/4 Cross multiply to get: 4G = 5B Rearrange to get: 4G - 5B = 0 Target question: What is the value of G Statement 1: If four ...” February 24, 2019 Brent@GMATPrepNow posted a reply to Kim has 40 percent more money than Sal and Sal has 20 in the Problem Solving forum “Let x = Phil''s money Sal has 20 percent LESS money than Phil So, Sal''s money = (Phil''s money) - (20% Phil''s money) = x - (20% of x) = x - 0.2x = 0.8x Kim has 40 percent more money than Sal So, Kim''s money = (Sal''s money) + (40% Sal''s money) = (0.8x) + (40% of 0.8x) = ...” February 24, 2019 Brent@GMATPrepNow posted a reply to A straight line in the xy-plane has a slope of 2 and a in the Problem Solving forum “The question conveniently gives us the information to write the equation of the line in slope y-intercept form, y = mx + b, where m = slope and b = the y-intercept. Line in the xy-plane has a slope of 2 and a y-intercept of 2 So, the equation of the line is: y = 2x + 2 On this line, what is ...” February 24, 2019 Brent@GMATPrepNow posted a reply to If y >= 0, What is the value of x? in the Data Sufficiency forum “Target question: What is the value of x? Given: y ≥ 0 Statement 1: |x - 3| ≥ y Let''s TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 10 and y = 2. We get |10 - 3| ≥ 2, which evaluates to be 7 ≥ 2, which satisfies ...” February 23, 2019 Brent@GMATPrepNow posted a reply to The total of company C's assets in 1994 was 300% greater in the Problem Solving forum “The total of company C''s assets in 1992 was N dollars Company C''s assets in 1993 was 400% greater than the total in 1992 So, 1993 assets = (1992 assets) + (400% of 1992 assets) = (N) + (400% of N) = (N) + (400/100 x N) = N + 4N = 5N Company C''s assets in 1994 was 300% greater than the ...” February 23, 2019 GMATGuruNY posted a reply to The total of company C's assets in 1994 was 300% greater in the Problem Solving forum “Let N dollars in 1992 = 1. Since the assets in 1993 are 300% greater than the N dollars in 1992, the assets in 1993 = 1 + (300% of 1) = 1+3 = 4. Since the assets in 1994 are 400% greater than the assets in 1993, the assets in 1994 = 4 + (400% of 4) = 4 + 16 = 20. The question stem asks for ...” February 23, 2019 Brent@GMATPrepNow posted a reply to At a bakery, the price of a bagel ranges between$0.65 and $in the Problem Solving forum “The least expensive price for a bagel is$0.65 If a customer purchases 12 bagels (at $0.65 each), then he/she receives 13 bagels. So, the minimum amount that a customer could pay to receive 13 bagels = 12 x$0.65 = $7.80 Answer: B Cheers, Brent” February 23, 2019 GMATGuruNY posted a reply to Andrew bought pizzas for his swim team. Pepperoni pizzas cos in the Problem Solving forum “13x + 17y = 184. Multiples of 13: 13, 26, 39, 52, 65, 78, 91, 104... Multiple of 17: 17, 34, 51, 68, 85, 102, 119.... The values in blue sum to 184. Since 65/13 = 5 and 119/17 = 7, the number of pizzas = 5+7 = 12. The correct answer is A.” February 23, 2019 GMATGuruNY posted a reply to Nathan took out a student loan for 1200$ at 10 percent in the Problem Solving forum
“Since the 10% rate is compounded annually, the amount of interest increases by 10% each year: First-year interest = 10% of 1200 = 120. Second-year interest = (first-year interest) + 10% = 120 + 12 = 132. Third-year interest = (second-year interest) + 10% = 132 + 13.2 = 145.2. Total interest = ...”
February 22, 2019
GMATGuruNY posted a reply to Ten theater students are to begin work on a set for a in the Problem Solving forum
“(50 days)/(60 days) = 5/6. To finish the job in 5/6 of the normal time, the crew requires 6/5 of the normal number of students -- an increase of 1/5: (1/5)(10) = 2 more students. The correct answer is A.”
February 22, 2019
Brent@GMATPrepNow posted a reply to a, b, and c are positive integers. Is a+b+c an odd number? in the Data Sufficiency forum
“ Given: a, b, and c are positive integers. Target question: Is a + b + c an odd number? Statement 1: ab is an odd number No information about c. NOT SUFFICIENT Statement 2: c is an odd number No information about a or b. NOT SUFFICIENT Statements 1 and 2 combined If ab ...”
February 22, 2019
Brent@GMATPrepNow posted a reply to In how many ways a cricket team consisting of 5 batsmen, 4 in the Problem Solving forum
“Take the task of creating a cricket team and break it into stages. Stage 1: Select 5 batsmen Since the order in which we select the batsmen does not matter, we can use combinations. We can select 5 batsmen from 7 batsmen in 7C5 ways (21 ways) So, we can complete stage 1 in 21 ways ...”
February 22, 2019
Brent@GMATPrepNow posted a reply to If 1/x-1/y=1/z, what is the value of y, in terms of x and z? in the Problem Solving forum
“We can also solve the question algebraically. GIVEN: 1/x - 1/y = 1/z Multiply both sides by x to get: 1 - x/y = x/z Multiply both sides by y to get: y - x = xy/z Multiply both sides by z to get: yz - xz = yx Rearrange to get y terms on one side: yz - yx = xz Factor left side: y(z - x) = ...”
February 22, 2019
GMATGuruNY posted a reply to In how many ways a cricket team consisting of 5 batsmen, 4 in the Problem Solving forum
“From 7 batsmen, the number of ways to choose 5 = 7C5 = (7*6*5*4*3)/(5*4*3*2*1) = 21. From 6 bowlers, the number of ways to choose 4 = 6C4 = (6*5*4*3)/(4*3*2*1) = 15. From 3 wicketkeepers, the number of ways to choose 1 = 3. From 3 allrounders, the number of ways to choose 1 = 3. To combine these ...”
February 22, 2019
GMATGuruNY posted a reply to How many different arrangements are possible to place seven in the Problem Solving forum
“Let the 3 math books = A, B, C and the remaining 4 books = D, E, F, G. Since the 3 math books must be next to one another, put them together in a block: E.”
February 22, 2019
GMATGuruNY posted a reply to If 1/x-1/y=1/z, what is the value of y, in terms of x and z? in the Problem Solving forum
“Let x=1 and y=3/2, with the result that 1/z = 1 - 2/3 = 1/3, so z=3. Since the question stem asks for the value of y, the correct answer must yield 3/2 when x=1 and z=3. Since B and D include x-z and thus will yield a negative result, eliminate B and D. Since E includes only multiplication and ...”
February 22, 2019
GMATGuruNY posted a reply to Is p^3 < p? in the Data Sufficiency forum
“Statements combined: Case 1: p=0, with the result that p is an integer less than 1 In this case, p³=p, so the answer to the question stem is NO. Case 2: p=-2, with the result that p is an integer less than 1 In this case, p³ < p, so the answer to the question stem is YES. Since the answer ...”
February 22, 2019
GMATGuruNY posted a reply to In the figure shown, AB = AC = 12. Which of the following is in the Problem Solving forum
“https://i.postimg.cc/06HLPxqC/circle-in-a-sector.png AOP passes through the center of the inscribed circle and thus must BISECT sector ACB. AB, AP and AC are all radii of sector ACB and thus are equal. The prompt indicates AB=AC=12. Thus: AP=12. As shown in the figure, AOM is a 30-60-90 ...”
February 22, 2019
Brent@GMATPrepNow posted a reply to Last year the range of the annual salaries of the 100 in the Problem Solving forum
“A quick solution is to assign some values to the highest paid and lowest paid workers Let $10,000 = the lowest salary LAST YEAR Let$40,000 = the highest salary LAST YEAR This satisfies the condition that the range LAST YEAR = $30,000 If the annual salary of each of the 100 employees this ...” February 21, 2019 GMATGuruNY posted a reply to The sum of two integers is 27. The larger integer is 25% in the Problem Solving forum “25% greater = 1/4 greater. If the smaller integer = 4, then the larger integer = 4 + (1/4)4 = 5. The values in red imply that the two integers summing to 27 must be in a RATIO OF 4 TO 5: 4, 5 8, 10 12, 15 The case in blue sums to 27, with the result that larger-smaller = 15-12 = 3. The ...” February 21, 2019 Brent@GMATPrepNow posted a reply to The sum of two integers is 27. The larger integer is 25% in the Problem Solving forum “Let x = the smaller integer So, 1.25x = the larger integer (since the larger integer is 25% greater than the smaller integer) The sum of two integers is 27. We can write: x + 1.25x = 27 Simplify: 2.25x = 27 Solve: x = 27/2.25 IMPORTANT: What''s a nice fast way to evaluate 27/2.25? An easy ...” February 21, 2019 Brent@GMATPrepNow posted a reply to What is the greatest positive three-digit number that is div in the Problem Solving forum “One approach is to check each answer choice, beginning with the largest answer choice E. 840 840 is divisible by 2, 3, 4, 5, 6 and 7 Answer: E Cheers, Brent” February 21, 2019 Brent@GMATPrepNow posted a reply to What is the largest digit n for which the number 123,45n is in the Problem Solving forum “RULE: if the SUM of the digits of a number is divisible by 3, then that number is divisible by 3 Take, for example, the number 1,001,226 1 + 0 + 0 + 1 + 2 + 2 + 6 = 12 Since 12 is divisible by 3, we know that 1,001,226 is divisible by 3 If 123,45n is divisible by 3, then 1 + 2 + 3 + 4 + 5 + n ...” February 21, 2019 Brent@GMATPrepNow posted a reply to In the figure above, the angle marked at c has been created in the Data Sufficiency forum “Target question: What is the sum of a, b, and c? This is a good candidate for rephrasing the target question. Since angles on a line add to 180°, we already know that b + c = 180 We get: a + b + c = a + 180 So, in order to find the sum of a, b and c, we need only find the value of a ...” February 21, 2019 GMATGuruNY posted a reply to In the figure above, the angle marked at c has been created in the Data Sufficiency forum “Since b and c form a straight line, b+c = 180. Thus, the calculate a+b+c, we need to know the value of a. Question stem, rephrased: What is the value of a? Statement 1: SUFFICIENT. Statement 2: No information about a. INSUFFICIENT. The correct answer is A.” February 21, 2019 Brent@GMATPrepNow posted a reply to At a certain committee meeting only associate professors and in the Problem Solving forum “Notice that the question asks us to find that TOTAL number of people present. In other words, it the question does NOT ask us to find the number of associate professors or assistant professors present. Since each person brings THREE items, and since total of 21 items were brought (10 pencils ...” February 21, 2019 GMATGuruNY posted a reply to At a certain committee meeting only associate professors and in the Problem Solving forum “Total number of items brought to the meeting = 21. (10 charts and 11 pencils) Number of items brought by each person = 3. (Either 2 pencils and 1 chart or 1 pencil and 2 charts) Thus: Number of people = (total number of items)/(number of items per person) = 21/3 = 7. The correct answer is B.” February 21, 2019 Brent@GMATPrepNow posted a reply to In a class of 30 students, 2 students did not borrow any in the Problem Solving forum “The average (arithmetic mean) number of book borrowed per student was 2. Since there are 30 students altogether, the total number of borrowed books = (2)(30) = 60 2 students borrowed 0 books: total of 0 books 12 students borrowed 1 book each: total of 12 books 10 students borrowed 2 books ...” February 21, 2019 Brent@GMATPrepNow posted a reply to If there are more than two numbers in a certain list, is in the Data Sufficiency forum “Target question: Is each of the numbers n the list equal to zero? Given: There are more than 2 numbers in the list Statement 1: The product of any 2 numbers in the list is ZERO There are several possible sets that satisfy this condition. Here are two: Case a: the set is {0, 0, 0} in ...” February 21, 2019 GMATGuruNY posted a reply to Four cards are chosen from a standard deck: two aces (one of in the Problem Solving forum “The following cases are possible: (-1)(1) = -1 (-1)(-2) = 2 (-1)(2) = -2 (1)(-2) = -2 (1)(2) = 2 (-2)(2) = -4 Of the 6 cases above, the 4 in blue each yield a product that is negative, odd or both: 4/6 = 2/3 ≈ 67%. The correct answer is D.” February 20, 2019 Brent@GMATPrepNow posted a reply to Is mn < 10? in the Data Sufficiency forum “Target question: Is mn < 10? Statement 1: m < 5 and n < 2 Let''s TEST some values. There are several values of m and n that satisfy statement 1. Here are two: Case a: m = 0 and n = 0. In this case mn = (0)(0) = 0. So, the answer to the target question is YES, mn IS less than 10 ...” February 20, 2019 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Data Sufficiency lesson #4: GMAT Data Sufficiency Strategies - Part I Video : https://www.youtube.com/watch?v=Ep09hi1OJpI Cheers, Brent” February 20, 2019 Brent@GMATPrepNow posted a reply to John takes 15 hours to complete a certain job, while Bill ta in the Problem Solving forum “Let''s first see what happens if Steven works as fast as possible. Since Bill can complete the job in 6 hours, Steven must complete the job in a little more than 6 hours. For example, we COULD see what happens if Steven takes 6.000000000000001 hours to complete the job. Unfortunately, ...” February 20, 2019 Brent@GMATPrepNow posted a reply to If x, y, and z are three-digit positive integers and if x = in the Data Sufficiency forum “Target question: Is the hundreds digit of x equal to the sum of the hundreds digits of y and z ? Notice that there are essentially 3 ways for the hundreds digit of x to be different from the sum of the hundreds digits of y and z Scenario #1: the hundreds digits of y and z add to more than 9. ...” February 20, 2019 Rich.C@EMPOWERgmat.com posted a reply to Which of the following points is the intersection between in the Problem Solving forum “Hi All, We''re asked which of the following points is the intersection between the lines y = 3x + 6 and y = -2x - 4. This question can be solved in a number of different ways, including by TESTing THE ANSWERS. Since we''re dealing with two lines - and we now that the two lines intersect - ...” February 19, 2019 Rich.C@EMPOWERgmat.com posted a reply to A certain taxi company charges$3.10 for the first 1/5 of in the Problem Solving forum
“Hi All, We''re told that a certain taxi company charges $3.10 for the first 1/5 of a mile plus$0.40 for each additional 1/5 of a mile. We''re asked for the total charge for a taxi ride that was 8 miles long? The prompt gives us the price per 1/5 of a mile for a taxi ride. It''s worth noting ...”
February 19, 2019
Rich.C@EMPOWERgmat.com posted a reply to George bought a large electronic item with a 15% off coupon in the Problem Solving forum
“Hi All, We''re told that George bought a large electronic item with a 15% off coupon and paid a total bill. When he got outside, he studied the receipt and realize that he mistakenly had been given DOUBLE the discount of the coupon, even though there was no double-coupon offer in effect that ...”
February 19, 2019
Brent@GMATPrepNow posted a reply to George bought a large electronic item with a 15% off coupon in the Problem Solving forum
“George was SUPPOSED to receive a 15% discount, but he received a 30% discount. So, he should have returned 15% of the original cost. However, the manager asked for half that amount (i.e., 7.5% of the original cost) In other words, 7.5% of the original cost = $40.50 IMPORTANT: at this point, ...” February 19, 2019 Brent@GMATPrepNow posted a reply to Is x-y+1 greater than x+y-1 ? in the Data Sufficiency forum “Target question: Is x - y + 1 > x + y - 1 ? This is a good candidate for rephrasing the target question. Take: x - y + 1 > x + y - 1 Subtract x from both sides to get: -y + 1 > y - 1 Add y to both sides to get: 1 > 2y - 1 Add 1 to both sides to get: 2 > 2y Divide both ...” February 19, 2019 Brent@GMATPrepNow posted a reply to Anna has to visit at least 2 European cities on her vacation in the Problem Solving forum “We need to consider 3 different cases: i) Anna visits 2 cities ii) Anna visits 3 cities iii) Anna visits 4 cities i) Anna visits 2 cities There are 4 options for the FIRST city and 3 options for the SECOND city So, the total number of 2-city itineraries = (4)(3) = 12 ii) Anna visits 3 ...” February 19, 2019 Brent@GMATPrepNow posted a reply to Which of the following points is the intersection between in the Problem Solving forum “KEY CONCEPT: The point of intersection (call P) of the lines y = 3x + 6 and y = -2x - 4 will be such that the x- and y-coordinates of P will satisfy BOTH equations. Since both equations are set equal to y, we can write: 3x + 6 = -2x - 4 Add 2x to both sides: 5x + 6 = - 4 Subtract 6 from both ...” February 19, 2019 GMATGuruNY posted a reply to A box contains 1 red ball, 3 green balls, 5 yellow balls, 7 in the Problem Solving forum “Determine the WORST-CASE-SCENARIO -- for each color of ball, the MAXIMUM number that can be removed WITHOUT removing 7 of the same color: 1 red 3 green 5 yellow 6 blue 6 white 6 black Sum = 1+3+5+6+6+6 = 27. Implication: It is possible to remove 27 balls without selecting 7 of the same ...” February 19, 2019 GMATGuruNY posted a reply to If M, N are integers greater than 1 such that 2M<N, which in the Problem Solving forum “54, 52 and 50 are options for TWICE the sum. Thus, I, II, and III imply the following options for the ACTUAL SUM: I: 27 II: 26 III: 25 Case 1: M=2 Since it is required that N>2M, N≥5 M=2 and N=5 --> sum = 2+3+4+5 = 14 M=2 and N=6 --> sum increases by 6 --> 14+6 = 20 M=2 and ...” February 19, 2019 GMATGuruNY posted a reply to If A and B are two fixed constants such that the system in the Problem Solving forum “The system will have an infinite number of solutions for (x, y) if the two equations are THE SAME: 2(x+y) - A = 0 --> 2x + 2y - A = 0 --> 6x + 6y - 3A = 0 3x + By - 6 = 0 -----------------------> 6x +2By - 12 = 0 The equations in blue will be the same if 3A=12 and 2B=6, with the result ...” February 18, 2019 OfficialGMAT posted a reply to GMAT prep in the Lounge forum “Please visit mba.com/exam-prep for more information on the most up-to-date GMAT prep materials. In addition, you can visit the following page to learn about study timing and pacing, which also has a link to our 8-week Study Plan that may help you map out a plan for success. Good luck!” February 18, 2019 Brent@GMATPrepNow posted a reply to How many positive perfect cubes are divisors of 4^6? in the Problem Solving forum “4⁶ = (2²)⁶ = 2¹² Since 2¹² = (2³)(2⁹), we know 2³ is a divisor of 2¹² Since 2¹² = (2⁶)(2⁶), we know 2⁶ is a divisor of 2¹² Since 2¹² = (2⁹)(2³), we know 2⁹ is a divisor of 2¹² Since 2¹² = (2¹²)(2⁰), we know 2¹² is a divisor of 2¹² Since 2¹² = ...” February 18, 2019 Brent@GMATPrepNow posted a reply to The squares of two consecutive positive integers differ by 5 in the Problem Solving forum “Let x = the smaller integer So, x+1 = the larger integer (since the numbers are CONSECUTIVE) The squares of two consecutive positive integers differ by 55. We can write: (x + 1)² - x² = 55 Expand: x² + 2x + 1 - x² = 55 Simplify: 2x + 1 = 55 So: 2x = 54 Solve: x = 54/2 = 27 Answer: ...” February 18, 2019 GMATGuruNY posted a reply to Is m > n? in the Data Sufficiency forum “Both statements are satisfied if n=1 and m=2 or if n=1 and m=-2. Since m > n in the first case but m < n in the second case, the two statements combined are INSUFFICIENT. The correct answer is E.” February 18, 2019 GMATGuruNY posted a reply to If the original price of an item in a retail store is marked in the Data Sufficiency forum “Let the original price = 100. Then the markup = (m/100)*100 = m. The resulting price = 100+m. The subsequent discount = d/100*(100+m) = d + md/100 Thus, the total percent change = percent increase - percent decrease = m - d - md/100. For the final price to be greater than the original price, ...” February 17, 2019 GMATGuruNY posted a reply to In triangle ABC, point X is the midpoint of side AC and poin in the Data Sufficiency forum “http://s7.postimage.org/6u5drpql3/triangle_RCS_1.jpg Triangles RCS and ABC: Side RC = 1/4(AC). Side SC = 1/4(BC). The two triangles share angle BCA. Triangles with a shared angle (BCA) formed by corresponding sides in the same proportion (RC:AC = 1:4, SC:BC = 1:4) are SIMILAR. Thus, ...” February 17, 2019 GMATGuruNY posted a reply to A and B start from Opladen and Cologne respectively at the in the Problem Solving forum “When two elements travel at different speeds, their TIME RATIO to travel the same distance will always be the same. If A takes 1/2 as long as B to travel 10 miles, then A will take 1/2 as long as B to travel 1000 miles. If A takes 3 times as long as B to travel 500 miles, then A will take three ...” February 17, 2019 GMATGuruNY posted a reply to Flor is choosing three of five colors of paint to use for in the Problem Solving forum “Let the 5 colors be GYABC. From the 5 colors, the number of ways to choose 3 = 5C3 = (5*4*3)/(3*2*1) = 10. Of these 10 combinations, 3 are not allowed: GYA GYB GYC Subtracting these 3 bad combinations, we get: 10-3 = 7. The correct answer is A.” February 17, 2019 Brent@GMATPrepNow posted a reply to A scientist has 400 units of a 6% phosphoric acid solution, in the Problem Solving forum “We can solve this question with the weighted averages formula: Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ... Let x = the number of units of 12% phosphoric acid solution needed ...” February 16, 2019 Brent@GMATPrepNow posted a reply to If a = 15! + 13, which of the following are factors of a? I in the Problem Solving forum “Here''s a similar question to practice with: https://www.beatthegmat.com/divisibility-t111432.html Cheers, Brent” February 16, 2019 Brent@GMATPrepNow posted a reply to Phone plan A charges$1.25 for the first minute and $0.15 in the Problem Solving forum “Phone plan A charges$1.25 for the first minute and $0.15 for every minute thereafter. Let x = total duration of phone call (in minutes) So, the cost of an x-minute call =$1.25 + ($0.15)(x - 1) ASIDE: I created the expression ($0.15)(x - 1) because we pay $1.25 for the FIRST minute. So, if x = ...” February 16, 2019 Brent@GMATPrepNow posted a reply to A magician has five animals in his magic hat: 3 doves and 2 in the Problem Solving forum “Let''s apply probability rules First notice that, to get a matched pair, we can select 2 doves or 2 rabbits. So, P(matched pair) = P(1st pick is rabbit AND 2nd pick is rabbit OR 1st pick is dove AND 2nd pick is dove) We can now apply our AND and OR rules to get: P(matched pair) = x P(2nd ...” February 16, 2019 GMATGuruNY posted a reply to If a = 15! + 13, which of the following are factors of a? I in the Problem Solving forum “MULTIPLE OF X + MULTIPLE OF X = MULTIPLE OF X. MULTIPLE OF X + NON-MULTIPLE OF X = NON-MULTIPLE OF X. Since the prime-factorization of 15! includes 13, we get: a = 15! + 13 = multiple of 13 + multiple of 13 = multiple of 13. Since a is a multiple of 13, option I is a factor of a. Eliminate ...” February 16, 2019 GMATGuruNY posted a reply to If a coin has an equal probability of landing heads up or ta in the Problem Solving forum “P(H) = 1/2. P(T) = 1/2. One way to get exactly 1 heads in 3 flips: P(HTT) = 1/2 * 1/2 * 1/2 = 1/8. Since H can appear in a total of 3 positions -- 1st flip, 2nd flip, or 3rd flip -- we multiply by 3: 1/8 * 3 = 3/8 = 0.375. The correct answer is C.” February 16, 2019 GMATGuruNY posted a reply to A magician has five animals in his magic hat: 3 doves and 2 in the Problem Solving forum “AND means MULTIPLY. OR means ADD. Case 1: 2 doves P(1st animal is a dove) = 3/5. (Of the 5 animals, 3 are doves.) P(2nd animal is a dove) = 2/4. (Of the 4 remaining animals, 2 are doves.) Since in Case 1 we need the 1st animal to be a dove AND the 2nd animal to be a dove, we MULTIPLY the ...” February 16, 2019 Rich.C@EMPOWERgmat.com posted a reply to Working at their individual same constant rate, 24 machines in the Problem Solving forum “Hi All, We''re told that while working at their individual same constant rate, 24 machines can complete a certain production job in 10 hours when they all work together. However, on a certain day, due to minor malfunction, 8 of those machines were not operating for the first 2 hours. We''re ...” February 15, 2019 Rich.C@EMPOWERgmat.com posted a reply to If a positive integer q is divisible by both 3 and 11, then in the Problem Solving forum “Hi All, We''re told that Q is a positive integer that is divisible by BOTH 3 and 11. We''re asked which of the following MUST also divisible evenly into Q. This question can be approached in a couple of different ways, including by TESTing VALUES. With these types of prompts, it often helps ...” February 15, 2019 Brent@GMATPrepNow posted a reply to If a positive integer q is divisible by both 3 and 11, then in the Problem Solving forum “I. 14 14 is NOT divisible by 3 or 11 So, statement I is NOT true. ELIMINATE A and D III. 66 Integer q COULD equal 33 (which is divisible by 3 and 11) Since 33 is NOT divisible by 66, statement III is NOT true. ELIMINATE C and E By the process of elimination, the correct answer is B ...” February 15, 2019 Brent@GMATPrepNow posted a reply to Kevin buys beer in bottles and cans. He pays$1.00 for each in the Data Sufficiency forum
“Target question: How many bottles of beer did Kevin buy? Given: Kevin pays $1.00 for each can of beer and$1.50 for each bottle of beer. Kevin buys a total of 15 bottles and cans of beer Let C = the NUMBER of Cans that Kevin bought Let B = the NUMBER of Bottles that Kevin bought So, we can ...”
February 15, 2019
GMATGuruNY posted a reply to What is the value of (2^{2020} + 2^{2018}) / (2^{2020}-2^{20 in the Problem Solving forum
“(2²⁰²⁰ + 2²⁰¹⁸)/(2²⁰²⁰ - 2²⁰¹⁸) = (2²⁰¹⁸)(2² + 1) / (2²⁰¹⁸)(2² - 1) = 5/3. The correct answer is B.”
February 15, 2019
GMATGuruNY posted a reply to If Rebeca drives to work at x mph she will be one minute lat in the Data Sufficiency forum
“In deference to your mother, the offensive second "c" has been removed from my solution.”
February 15, 2019
GMATGuruNY posted a reply to A certain military vehicle can run on pure Fuel X, pure Fuel in the Data Sufficiency forum
“Statement 1: X = 20 miles per gallon. Y = 40 miles per gallon. Since the mixture of X and Y in the tank allows 200 miles to be covered using 8 gallons, we get: X+Y = 200/8 = 25 miles per gallon. To determine how X and Y must be combined to yield a rate of 25 miles per gallon, use ALLIGATION. ...”
February 15, 2019
GMATGuruNY posted a reply to If Rebeca drives to work at x mph she will be one minute lat in the Data Sufficiency forum
“To make the math easier, we can replace the given values with rounder numbers, as follows: Since Rebeca arrives 1 hour late when traveling at the lower speed and 1 hour early when traveling at the higher speed, the time at the lower speed must be 2 hours greater than the time at the higher ...”
February 15, 2019
GMATGuruNY posted a reply to Which of the following numbers is closest to 100*(11-sqrt( in the Problem Solving forum
“100(11 - √119)(11 + √119) = 100(11² - √119²) = 100(121-119) = 100*2 = 200. When the correct answer is multiplied by 11+√119, the result must be as close as possible to 200. 11+√119 = 11 + (a bit less than 11) = a bit less than 22. Since 9*22 = 198, multiplying 9.2 by a bit less than ...”
February 14, 2019
GMATGuruNY posted a reply to What is the value of a^3+b^3 ? in the Data Sufficiency forum
“Statement 1: Case 1: a=0 and b=1, with the result that a+b = 0+1 = 1 In this case, a³+b³ = 0³ + 1³ = 1 Case 2: a=2 and b=-1, with the result that a+b = 2-1 = 1 In this case, a³+b³ = 2³ + (-1)³ = 7 Since a³+b³ can be different values, INSUFFICIENT. Statement 2: Case 3: a=1 and b=1, ...”
February 14, 2019
GMATGuruNY posted a reply to A group of x people is practicing levitation yoga. One-fourt in the Problem Solving forum
“Let x=12. Since 1/4 of the people rise up, the number who rise up = (1/4)(12) = 3. Since 3 people come back down, EVERYONE who rises up comes back down, with the result that all 12 people are practicing yoga on the ground. How many people are now practicing yoga on the ground? The correct ...”
February 14, 2019
Brent@GMATPrepNow posted a reply to A group of x people is practicing levitation yoga. One-fourt in the Problem Solving forum
“ One-fourth of the people rise up in the air If 1/4 of the x people are in the AIR, the remaining 3/4 of the x people are on the GROUND So, (3/4)x = number of people on the GROUND After a while, 3 of them come back down. So, the number of people on the GROUND is increased by 3 So, now ...”
February 14, 2019
Brent@GMATPrepNow posted a reply to In the figure above, polygon N has been partially covered by in the Data Sufficiency forum
“Target question: How many sides does N have? Statement 1: x + y = 45 Since all angles in a triangle add to 180°, we know that the missing angle is 135° https://i.imgur.com/oUCDRTN.png There are plenty of polygons that have at least one angle measuring 135°. Here are two: Case a: ...”
February 14, 2019
Brent@GMATPrepNow posted a reply to Which of the following expressions is equal to 2^32-2^31-2^3 in the Problem Solving forum
“2^32 - 2^31 - 2^30 = (2^30)(2^2 - 2^1 - 1) = (2^30)(4 - 2 - 1) = (2^30)(1) = 2^30 Answer: C Cheers, Brent”
February 14, 2019
Brent@GMATPrepNow posted a reply to OG L-shaped garden in the Data Sufficiency forum
“Target question: What is the value of k? Statement 1: The area of the garden is 189 square feet. Let''s drawn an auxiliary line that divides the shape into two rectangular regions A and B. https://i.imgur.com/hJBOxsO.png Regions A and B have the following measurements. ...”
February 13, 2019
Brent@GMATPrepNow posted a reply to How many integers between 18 and 3399 are multiples of 17? in the Problem Solving forum
“Let''s list the multiples of 17 that are between 18 and 3399 : 34 = 2(17) 51 = 3(17) 68 = 4(17) 85 = 5(17) . . . 3383 = 199(17) So, the number of multiples of 17 is EQUAL to the number of integers from 2 to 199 inclusive ASIDE: A nice rule says: the number of integers from x to y ...”
February 13, 2019
Brent@GMATPrepNow posted a reply to A mountain resort will hold its annual one-day snowboarding in the Problem Solving forum
“GIVEN: P(snow) = 0.7, so P(no snow) = 0.3 Let''s use the complement to solve this. That is, P(event is held) = 1 - P(event is NOT held) P(event is NOT held) = P(no snow on Saturday AND no snow on Sunday) = P(no snow on Saturday) x P(no snow on Sunday) = 0.3 x 0.3 = 0.09 So, P(event is ...”
February 13, 2019
GMATGuruNY posted a reply to How many prime factors does the number X have? 1) X is divi in the Data Sufficiency forum
“Statement combined: Case 1: X = 53*2 = 106, with the result that X is divisible by 1, 2, 53, and 106 In this case, X has TWO prime factors: 2 and 53 Case 2: X = 53³, with the result that X is divisible by 1, 53, 53², and 53³ In this case, X has only ONE prime factor: 53 Since the number of ...”
February 13, 2019
Brent@GMATPrepNow posted a reply to The product P of two prime numbers is between 9 and 55. in the Problem Solving forum
“Prime numbers that are greater than 2 but less than 6: 3, 5 Prime numbers that are greater than 13 but less than 25: 17, 19, 23 Scan the answer choices . . . E) 51 = 3 x 17 PERFECT! Answer: E Cheers, Brent”
February 12, 2019
GMATGuruNY posted a reply to A terminating decimal is a number with a finite number of in the Data Sufficiency forum
“A fraction will yield a terminating decimal if -- when the fraction is fully reduced -- the prime-factorization of its denominator includes only 2''s and or 5''s. Statement 1: Let x = an odd multiple of 5. Since the next largest odd multiples of 5 will be x+10 and x+20, we get: p = x + (x+10) ...”
February 12, 2019
GMATGuruNY posted a reply to If O is the center of the circle with diameter AB and T is a in the Problem Solving forum
“A radius drawn to a tangent point yields a RIGHT ANGLE: https://i.postimg.cc/Wq6BDNH7/two-triangles-and-semicircle-1.png In the figure above: Radius OT forms a right angle at tangent point T. OA and OT are radii and thus are equal. Since OA=OT, opposite angles OAT and ATO are equal. We can ...”
February 12, 2019
Brent@GMATPrepNow posted a reply to What is the probability that you get a pair when picking the in the Problem Solving forum
“P(select pair) = P(1st card is ANY card AND 2nd card matches 1st card) = P(1st card is ANY card) x P(2nd card matches 1st card) = 1 x 3/51 = 3/51 = 1/17 = C Aside: P(2nd card matches 1st card) = 3/51, because once 1 card is selected, there are 51 cards remaining in the deck. Among those 51 ...”
February 12, 2019
Brent@GMATPrepNow posted a reply to At her current job, Mary gets a 1.5% raise twice per year. in the Problem Solving forum
“One approach here is to apply the COMPOUND INTEREST formula. However, if you didn''t see that the question is analogous to a COMPOUND INTEREST question, we can also solve the question by looking for a pattern. Let''s try that: Time elapsed (in years) | salary 0 | s 0.5 | (1.015)(s) 1 | ...”
February 12, 2019
Brent@GMATPrepNow posted a reply to Of the 3,000 cars manufactured in Factory Q last year, how in the Data Sufficiency forum
“Target question: Of the 3,000 cars manufactured in Factory Q LAST YEAR, how many were still in operation at the end of the year? Neither statement provides any information about the cars manufactured LAST YEAR. Instead, we''re told about ALL of the cars ever manufactured . As such, the ...”
February 12, 2019
GMATGuruNY posted a reply to A positive 5-digit integer is called "friendly" if in the Problem Solving forum
“Total number of friendly numbers = total number of ways to arrange the 5 digits = 5! = 120. There are 5 options for the first digit: 1, 2, 3, 4, or 5. 120/5 = 24. Thus, the 120 friendly numbers are composed of five 24-number ranges, as follows: The integers beginning with 1 constitute friendly ...”
February 12, 2019
Brent@GMATPrepNow posted a reply to In the figure given, x = 3(y-z). What is the value of x? in the Problem Solving forum
“Since angles on a LINE add to 180°, . . . https://i.imgur.com/kAdhC7N.png . . . we know that x + z = 180 Subtract x from both sides to get: z = 180 - x Since angles in a CIRCLE add to 360°. . . https://i.imgur.com/l1SKqw5.png . . . we know that 60 + (180 - x) + y = 360 Simplify left ...”
February 12, 2019
Brent@GMATPrepNow posted a reply to In the xy-coordinate plane, if the point (0,2) lies on the g in the Problem Solving forum
“KEY CONCEPT: In order for a point to be ON a line, the x- and y-coordinates of the point must satisfy the equation of that line So, for example, the point (3,7) lies ON the line defined by the equation y = 2x + 1, because x = 3 and y = 7 satisfy the equation y = 2x + 1 That is, 7 = 2(3) + 1 ...”
February 12, 2019
Brent@GMATPrepNow posted a reply to Set S consists of n consecutive integers, where n > 1. in the Data Sufficiency forum
“ Given: Set S consists of n consecutive integers, where n > 1. Target question: What is the value of n? IMPORTANT: Notice that the two statements are VERY SIMILAR. That is, if the sum of the values is 14 (statement 2), then it is guaranteed that the sum is divisible by 7 (statement 1). ...”
February 12, 2019
GMATGuruNY posted a reply to How many numbers between 1 and 200, inclusive, have a 2 in in the Problem Solving forum
“An integer is divisible by 4 if its last two digits form a multiple of 4. Two-digit multiples of 4 with a units digit of 2: 12, 32, 52, 72, 92 Since the last two digits must be one of the options above, between 1 and 200 there are 10 integers that have a units digit of 2 and are divisible by 4: ...”
February 12, 2019
GMATGuruNY posted a reply to If triangles ABC and CDE are each equilateral, what is the s in the Data Sufficiency forum
“Statement 1: Case 1: AC = 10 and CE = 15, with the result that AE = 10+15 = 25 In this case, ABC + CDE = (10+10+10) + (15+15+15) = 75. Case 2: AC= 5 and CD = 20, with the result that AE = 5+20 = 25 In this case, ABC + CDE = (5+5+5) + (20+20+20) = 75. Since the sum of the perimeters is the same ...”
February 12, 2019
GMATGuruNY posted a reply to If m is a positive odd integer, what is the average (arithme in the Data Sufficiency forum
“For any EVENLY SPACED SET: average = median Statement 1: Here, the set consists of consecutive multiples of 3 and thus is evenly spaced. Case 1: 3, 6, 9 Average = median = 6. Case 2: 6, 9, 12 Average = median = 9. Since different averages are possible, INSUFFICIENT. Statement 2: Case ...”
February 12, 2019
GMATGuruNY posted a reply to If there is a 20% chance of rain every day for the next 7 in the Problem Solving forum
“Options D and E should appear as shown below: P(exactly n times) = P(one way) * all possible ways. Let R = rain and N = no rain. Since P(R) = 20% = 2/10, P(N) = 80% = 8/10 = 2³/10. P(one way): One way to get exactly 2 days of rain is to have rain on the first 2 days but not on the ...”
February 12, 2019
Brent@GMATPrepNow posted a reply to A computer chip manufacturer expects the ratio of the number in the Problem Solving forum
“Let''s find some TOTALS for all 4 shipments combined. There are 51,000 chips altogether There are 17 defective chips altogether. So, 17/51000 of the chips are defective. (notice that 17 divides nicely into 51000!) SIMPLIFY: 1/3000 of the chips are defective So, if we have a shipment of ...”
February 11, 2019
Brent@GMATPrepNow posted a reply to If O is the center of the circle with diameter AB and T is a in the Problem Solving forum
“Since angles in a triangle add to 180°, we know that the missing angle = (90 - 2x)° https://i.imgur.com/FcSiZi2.png Aside: Notice that (90 - 2x)° + 90° + 2x° =180° Since angles on a line add to 180°, we know that the missing angle = (90 + 2x)° https://i.imgur.com/9Z5ULFo.png ...”
February 11, 2019
Brent@GMATPrepNow posted a reply to tough geo. problem in the Data Sufficiency forum
“Target question: What is the length of side BC? Statement 1: Line segment AD has length 6. BEFORE we deal with statement 1, let''s see what information we can add to the diagram. For example, since ∆BDC has 2 equal angles (of 2x°), we know that side BD = side BC: ...”
February 11, 2019
Brent@GMATPrepNow posted a reply to What is the area of a right triangle? in the Data Sufficiency forum
“Target question: What is the area of a right triangle? Statement 1: The length of one side is 3 Knowing the length of only 1 side will not help us answer the target question with certainty. Statement 1 is NOT SUFFICIENT Statement 2: The length of one side is 4 NOT SUFFICIENT (same ...”
February 11, 2019
Brent@GMATPrepNow posted a reply to If x=0.2, then what is the value of x^3-1/x-1? in the Problem Solving forum
“Some spaces and/or brackets would definitely help here. Do you mean x^3 - 1/x - 1 or x^3 - 1/(x - 1) or (x^3 - 1)/(x - 1)?? Cheers, Brent”
February 11, 2019
Brent@GMATPrepNow posted a reply to If n and p are integers, is p > 0? in the Data Sufficiency forum
“ Given: n and p are integers Target question: Is p > 0? Statement 1: n + 1 > 0 No information about p. Statement 1 is NOT SUFFICIENT Statement 2: np > 0 There are several values of n and p that satisfy statement 2. Here are two: Case a: n = 1 and p = 1. In this case, ...”
February 11, 2019
Rich.C@EMPOWERgmat.com posted a reply to During the four years that Mrs. Lopez owned her car, she fou in the Problem Solving forum
“Hi All, We''re told that during the 4 years that Mrs. Lopez owned her car, she found that her total car expenses were $18,000. Fuel and maintenance costs accounted for 1/3 of the total and depreciation accounted for 3/5 of the REMAINDER. The cost of insurance was 3 times the cost of financing, ...” February 10, 2019 Rich.C@EMPOWERgmat.com posted a reply to At Megalomania Industries, factory workers were paid$20 per in the Problem Solving forum
“Hi All, We''re told that at Megalomania Industries, factory workers were paid $20 per hour in 1990 and$10 per hour in 2000 and the CEO of Megalomania Industries was paid $5 million per year in 1990 and$50 million per year in 2000. We''re asked for what percent greater was the percent increase ...”
February 10, 2019
Rich.C@EMPOWERgmat.com posted a reply to A company’s four cars running 10 hrs a day consume 1200 lt in the Problem Solving forum
“Hi All, We''re told that a company’s 4 cars running 10 hrs a day consume 1200 liters of fuel in 10 days. In the next 6 days, the company will need to run 9 cars for 12 hrs each so it rents 5 more cars which consume 20% less fuel than the company’s four cars. We''re asked for the number of ...”
February 10, 2019
Brent@GMATPrepNow posted a reply to If x and y are integers, is x^2-y^2 odd? in the Data Sufficiency forum
“Some important rules: #1. ODD +/- ODD = EVEN #2. ODD +/- EVEN = ODD #3. EVEN +/- EVEN = EVEN #4. (ODD)(ODD) = ODD #5. (ODD)(EVEN) = EVEN #6. (EVEN)(EVEN) = EVEN Target question: Is x² - y² odd? IMPORTANT: Notice that we can factor x² - y² to get: x² - y² = (x + y)(x - y) ...”
February 10, 2019
Brent@GMATPrepNow posted a reply to In a group of 100 adults, 75 percent of the women are in the Problem Solving forum
“GIVEN: 75% women are LEFT handed This also tells us that 25% women are RIGHT handed GIVEN: There are 12 right-handed women Let W = total number of women in the group So, 25% of W = 12 Rewrite as: 0.25W = 12 Solve: W = 12/0.25 = 48 So, there are 48 women So, the number of men in the ...”
February 10, 2019
GMATGuruNY posted a reply to Working together, Machine A and Machine B can produce a tota in the Data Sufficiency forum
“Since A+B take 4 hours to produce 200 widgets, the combined rate for A+B = w/t = 200/4 = 50 widgets per hour. To determine A''s time to produce 200 widgets, we need to know A''s rate. Question stem, rephrased: What is A''s rate? Statement 1: Since B takes 5 hours to produce 50 widgets, ...”
February 10, 2019
Brent@GMATPrepNow posted a reply to Triangle XYZ is an isosceles right triangle. If side XY is l in the Problem Solving forum
“Triangle XYZ is an isosceles right triangle. Let''s sketch an isosceles right triangle: https://i.imgur.com/N3UOppf.png Side XY is longer than side YZ Since the hypotenuse is the longest side of a right triangle, side XY must be the hypotenuse. Add this to our diagram: ...”
February 9, 2019
GMATGuruNY posted a reply to Triangle XYZ is an isosceles right triangle. If side XY is l in the Problem Solving forum
“The sides of an isosceles right triangle are in the following ratio: x - x - x√2, where x and x constitute the base and height and x√2 is the hypotenuse. Since the triangle has a base of x, a height of x, and an area of 16, we get: (1/2)(x)(x) = 16 x² = 32 x = √32 Since XY is longer ...”
February 9, 2019
GMATGuruNY posted a reply to Machines X and Y work at their respective constant rates. Ho in the Data Sufficiency forum
“Statement 1: Time and rate are RECIPROCALS. Since X and Y together take 2/3 as long as X alone, X and Y together work 3/2 as fast as X alone. Thus, if X''s rate alone = 2 units per hour, then X and Y''s combined rate = (3/2)(2) = 3 units per hour, implying that Y''s rate alone = 3-2 = 1 unit ...”
February 9, 2019
GMATGuruNY posted a reply to Seven children — A, B, C, D, E, F, and G — are going to in the Problem Solving forum
“Since A and B must occupy adjacent positions, consider AB a single element in the arrangement. The number of ways to arrange the 6 elements AB, C, D, E, F and G = 6! = 720. In 1/2 of these arrangements, C will be to the LEFT of AB. In the remaining 1/2 of these arrangements,C will be to the ...”
February 9, 2019
GMATGuruNY posted a reply to Is abc at least 4? in the Data Sufficiency forum
“Nice problem, Fabio! Statement 1: Case 1: a=4, b=1 and c=1, with the result that b+c≥2 In this case, abc = 4, so the answer to the question stem is YES. Case 2: a=0, b=1 and c=1, with the result that b+c≥2 In this case, abc = 0, so the answer to the question stem is NO. Since the answer ...”
February 8, 2019
Rich.C@EMPOWERgmat.com posted a reply to 530 to 700 in 3 months- possible? best strategy/study plan? in the GMAT Strategy forum
“Hi mgec0424, To start, a 520 is a decent initial CAT Score (the average Score on the Official GMAT hovers around 550 most years). Scoring 530 on your second CAT isn''t necessary a ''bad'' thing either - since it takes time to properly use what you''ve learn and adapt your approach to the overall ...”
February 8, 2019
GMATGuruNY posted a reply to What is the remainder when the positive integer n is divided in the Data Sufficiency forum
“Statement 1: If n=5, then the remainder when n is divided by 6 = 5/6 = 0 R5. If n=10, then the remainder when n is divided by 6 = 10/6 = 1 R4. Since different remainders are possible, INSUFFICIENT. Statement 2: Since n is a multiple of 12, n must also be a multiple of 6, with the result that ...”
February 8, 2019
GMATGuruNY posted a reply to An electrical supplies store sells 140 power stabilizer in the Problem Solving forum
“Since at least $5600 in profit must be earned by 140 units, the minimum required markup per unit = 5600/140 =$40. Thus, the minimum selling price = (cost per unit) + (minimum required markup per unit) = 16+40 = 56. The correct answer is D.”
February 8, 2019
Brent@GMATPrepNow posted a reply to Out of 2 broken TV sets and 6 fixed TV sets in Joe's Fix-My- in the Problem Solving forum
“There are 8 TV''s in total 2 are broken 6 are fixed We want to find P(at least one TV is broken) When it comes to probability questions involving at least, it''s often best to try using the complement. That is, P(Event A happening) = 1 - P(Event A not happening) So, here we get: P(getting ...”
February 8, 2019
Brent@GMATPrepNow posted a reply to An electrical supplies store sells 140 power stabilizer in the Problem Solving forum
“Let x = the selling price per unit So, x - 16 = the PROFIT on ONE unit And 140(x - 16) = the PROFIT on the sale of 140 units (aka the weekly profit) What is the minimum selling price per unit that will ensure a weekly profit of at least $5600 from sales of power stabilizers? In other words, ...” February 8, 2019 Brent@GMATPrepNow posted a reply to What is the remainder when the positive integer n is divided in the Data Sufficiency forum “Target question: What is the remainder when the positive integer n is divided by 6? Statement 1: n is multiple of 5 Let''s TEST some values. There are several values of n that satisfy statement 1. Here are two: Case a: n = 10. In this case, the answer to the target question is the ...” February 8, 2019 GMATGuruNY posted a reply to In the xy coordinate plane, line L and line K intersect at in the Data Sufficiency forum “Statement 1: The product of the x-intercepts of line L and K is positive. K has a negative x-intercept, L has a negative x-intercept, the product of the slopes is positive: http://s4.postimage.org/ie5nbe78/lines_l_and_k_1.jpg K has a positive x-intercept, L has a positive x-intercept, the ...” February 8, 2019 GMATGuruNY posted a reply to If x and y are positive integers, is x an even integer? in the Data Sufficiency forum “Statements combined: Case 1: x=1 and y=1, with the result that x(y+5) = 6 and 6y²+41y+25 = 72 In this case, x is ODD, so the answer to the question stem is NO. Case 2: x=2 and y=1, with the result that x(y+5) = 12 and 6y²+41y+25 = 72 In this case, x is EVEN, so the answer to the question ...” February 7, 2019 GMATGuruNY posted a reply to What is the average (arithmetic mean) of x and y? in the Data Sufficiency forum “SUM = (COUNT)(AVERAGE). Statement 1: x+y+k = (count)(average) = 3*7 = 21. No way to determine the value of x+y. INSUFFICIENT. Statement 2: x+y+3k = (count)(average) = 3*13 = 39. No way to determine the value of x+y. INSUFFICIENT. Statements combined: Subtracting x+y+k=21 from ...” February 7, 2019 GMATGuruNY posted a reply to If a and b are integers, is a + b + 3 an odd integer? (1) in the Data Sufficiency forum “a+b+3 = ODD only if a and b are both odd or both even. Question stem, rephrased: Are a and b both odd or both even? Statement 1: ab = ODD implies that a and b are both odd. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: a-b = EVEN implies that a and b are either ...” February 7, 2019 Brent@GMATPrepNow posted a reply to What is the sum of the digits of the number (2^{2018})(5^{20 in the Problem Solving forum “Useful rule: (x^k)(y^k) = (xy)^k Example: (3^4)(7^4) = 21^4 (2^2018)(5^2019)(3^2) = (2^2018)((5^2018)(5^1))(3^2) = (2^2018)(5^2018)(5^1))(3^2) = (10^2018)(5^1))(3^2) = (10^2018)(5)(9) = (10^2018)(45) We know that (10^2018) = 1 followed by 2018 zeros So, (10^2018)(45) = 45 followed by ...” February 7, 2019 Brent@GMATPrepNow posted a reply to If a and b are integers, is a + b + 3 an odd integer? (1) in the Data Sufficiency forum “Target question: Is a + b + 3 an odd integer? Given: a and b are integers Statement 1: ab is an odd integer. Some useful rules: 1. ODD - ODD = EVEN 2. ODD - EVEN = ODD 3. EVEN - ODD = ODD 4. EVEN - EVEN = EVEN 5. (ODD)(ODD) = ODD 6. (ODD)(EVEN) = EVEN 7. (EVEN)(EVEN) = EVEN ...” February 7, 2019 Brent@GMATPrepNow posted a reply to The sides of a right triangle are consecutive even integers, in the Problem Solving forum “GIVEN: p = length of the longest side Since the side lengths are consecutive even integers, we can say: p - 2 = length of the 2nd longest side p - 4 = length of the shortest side NOTE: The longest side is the HYPOTENUSE. So, p = length of the HYPOTENUSE And p - 2 = length of one leg of ...” February 7, 2019 Brent@GMATPrepNow posted a reply to In the diagram above, O is the center of the circle. What is in the Data Sufficiency forum “Target question: What is the length of chord AC? Given: O is the center of the circle If O is the center of the circle, then AB is the circle''s DIAMETER If AB is the DIAMETER, then ∠C = 90°, because ∠C is an inscribed angle containing ("holding") the diameter. So, let''s ...” February 7, 2019 Rich.C@EMPOWERgmat.com posted a reply to Ten telegenic contestants with a variety of personality diso in the Problem Solving forum “Hi All, For Test Takers who know the Combination Formula, this question is a fairly straight-forward prompt. If you DON''T know the Combination Formula though, then here''s what it is and how to use it. Any time a prompt asks for "groups" or "combinations" of things, then the ...” February 7, 2019 Rich.C@EMPOWERgmat.com posted a reply to The sides of a right triangle are consecutive even integers, in the Problem Solving forum “Hi All, We''re told that the sides of a right triangle are CONSECUTIVE EVEN INTEGERS, and the length of the LONGEST side is P. We''re asked which of the following equations could be used to find P. This question can be solved in a couple of different ways, including by TESTing VALUES. To ...” February 7, 2019 Rich.C@EMPOWERgmat.com posted a reply to There are 13 hearts in a full deck of 52 cards. In a certain in the Problem Solving forum “Hi All, The probability of pulling a heart out of a full deck of cards is 13/52 = 1/4, so the probability of NOT pulling a heart out of a full deck = 1 - 1/4 = 3/4. The probability of pulling a heart on the THIRD try, and NOT pulling a heart on the first two tries is: (3/4)(3/4)(1/4) = ...” February 7, 2019 Brent@GMATPrepNow posted a reply to Ten telegenic contestants with a variety of personality diso in the Problem Solving forum “Let''s take the task of creating the teams and break it into stages. Stage 1: Select two 5 contestants to be in tribe A Since the order in which we select the contestants does not matter, we can use combinations. We can select 5 contestants from 10 contestants in 10C5 ways 10C5 = ...” February 7, 2019 Rich.C@EMPOWERgmat.com posted a reply to Starting with 0, a mathematician labels every non-negative i in the Problem Solving forum “Hi All, We''re told that starting with 0, a mathematician labels every non-negative integer as one of five types: alpha, beta, gamma, delta, or epsilon, in that repeating order as the integers increase. For instance, the integer 8 is labeled delta. We''re asked for the label on an integer that ...” February 7, 2019 OfficialGMAT posted a reply to Question about EMBA in the The Application Process forum “Hi phrenetic, Admissions requirements differ by school/program. I would recommend that you check with the programs that you are planning to apply to, for their specific requirement. If you are unsure of what programs would be a good fit, you can use our school finder toolto discover and connect ...” February 6, 2019 OfficialGMAT posted a reply to Guidance on study plan in the GMAT Strategy forum “Hi Szhao, You can find information about study timelines and pacing on mba.com here: https://www.mba.com/exams/gmat/before-the-exam/perform-your-best-on-test-day/how-long-should-you-study-for-the-gmat-exam. At the bottom of that page, you''ll find a link to our 8-week GMAT study timeline, which ...” February 6, 2019 OfficialGMAT posted a reply to Looking for ISB Interview guidance in the The Application Process forum “Hi Akshay, You can also reference useful articles on mba.com regarding interview preparation, tips, and commonly asked questions, including the following: https://www.mba.com/mbas-and-business-masters/articles/admissions-interviews/commonly-asked-business-school-interview-questions. Good ...” February 6, 2019 Brent@GMATPrepNow posted a reply to We define the harmonic mean of a set of numbers as the recip in the Problem Solving forum “What is the harmonic mean of 20 and 30? NOTE: 20 = 20/1 So, the reciprocal of 20 = 1/20 And the reciprocal of 30 = 1/30 The average of 1/20 and 1/30 = (1/20 + 1/30 )/2 = (3/60 + 2/60 )/2 = (5/60 )/2 = (5/60 )/(2/1) = (5/60 )(1/2) = 5/120 The reciprocal of 5/120 = 120/5 = 24 Answer: ...” February 6, 2019 Brent@GMATPrepNow posted a reply to A certain bag contains red, blue, and green marbles. What is in the Data Sufficiency forum “ Given: A certain bag contains red, blue, and green marbles. Let R = # number red marbles in the bag Let B = # number blue marbles in the bag Let G = # number green marbles in the bag Target question: What is the value of G/R? Statement 1: The number of blue marbles in the bag is two ...” February 6, 2019 Brent@GMATPrepNow posted a reply to If x is a nonzero number, which of the three numbers x, 1/x in the Data Sufficiency forum “ Given: x is a nonzero number Target question: Which of the three numbers x, 1/x and x² is greatest? Statement 1: -1 < x < 1 This statement doesn''t FEEL sufficient, so I''ll TEST some values. There are several values of x that satisfy statement 1. Here are two: Case a: x = ...” February 6, 2019 GMATGuruNY posted a reply to In the coordinate plane, Line A has a slope of -1 and an in the Problem Solving forum “Line A includes points (1, 0) and (a, b) and has a slope of -1. Thus: (b - 0)/(a-1) = -1 b = -a + 1 a+b = 1. The correct answer is B. The information about Line B is irrelevant.” February 5, 2019 GMATGuruNY posted a reply to In how many ways can a 4-letter word be formed from the in the Problem Solving forum “Alternate approach: Case 1: VVCC, where the first two letters are vowels and the last 2 letters are consonants Number of options for the first vowel = 4. (Any of the 4 vowels) Number of options for the second vowel = 3. (Any of the 3 remaining vowels) Number of options for the first consonant ...” February 5, 2019 Rich.C@EMPOWERgmat.com posted a reply to Three digits have been removed from each of the following in the Problem Solving forum “Hi All, We''re told that three digits have been removed from each of the following numbers and n = 25. We''re asked which of the numbers is equal to 3*2^(n-1). To start, the fact that three digits have been removed from each answer is irrelevant. When a GMAT question presents information ...” February 5, 2019 Rich.C@EMPOWERgmat.com posted a reply to The organizers of a conference offered a certain number of s in the Problem Solving forum “Hi All, We''re told that the organizers of a conference offered a certain number of simultaneous seminars with the intention that each seminar would be attended by 18 conference attendees. However, space limitations allowed only up to 15 conference attendees to participate in each of a number of ...” February 5, 2019 Rich.C@EMPOWERgmat.com posted a reply to At a school-wide athletic fair, five students won a combined in the Problem Solving forum “Hi All, We''re told that at a school-wide athletic fair, five students won a combined total of 20 ribbons, each of the five students won AT LEAST one ribbon and NO two students won the SAME number of ribbons. We''re asked for the greatest number of ribbons that the student with the ...” February 5, 2019 Rich.C@EMPOWERgmat.com posted a reply to In how many ways can a 4-letter word be formed from the in the Problem Solving forum “Hi regor60, I agree that this prompt is poorly-worded. The "intent" is to ask for every 4-letter arrangement that fits the given restrictions, INCLUDING "words" that do not appear in the dictionary (re: arrangements that are not actually words). GMAT question-writers are far ...” February 5, 2019 Rich.C@EMPOWERgmat.com posted a reply to In the coordinate plane, Line A has a slope of -1 and an in the Problem Solving forum “Hi All, We''re told that in the coordinate plane, Line A has a slope of -1 and an x-intercept of 1 and Line B has a slope of 2 and a y-intercept of -2. The two lines intersect at the point (a,b). We''re asked for the sum a and b. When dealing with lines, it often helps to write the given ...” February 5, 2019 Brent@GMATPrepNow posted a reply to Three sisters have an average (arithmetic mean) age of 25 in the Problem Solving forum “If the average age is 25, we can write: (sum of all 3 ages)/3 = 25 This means, the sum of all 3 ages = 75 If the median is 24, then we can express the ages in ascending order as follows: __ , 24, __ Since the sum of the ages is 75, we can MINIMIZE the age of the oldest girl by MAXIMIZING the ...” February 5, 2019 Brent@GMATPrepNow posted a reply to A contractor combined x tons of a gravel mixture that in the Data Sufficiency forum “Let''s use some weighted averages to solve this question Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ... Target question: What is the value of x ? Given: A contractor combined x ...” February 4, 2019 GMATGuruNY posted a reply to A contractor combined x tons of a gravel mixture that in the Data Sufficiency forum “x = 10% gravel y = 2% gravel. z = the MIXTURE of x and y = 5% gravel. To determine the required ratio of x to y, use ALLIGATION -- a very efficient way to handle MIXTURE PROBLEMS. Step 1: Plot the 3 percentages on a number line, with the percentages for x and y on the ends and the ...” February 4, 2019 Rich.C@EMPOWERgmat.com posted a reply to Work/Rate problem in the Problem Solving forum “Hi benjemin28, It''s worth noting that he Quant section of the GMAT is NOT a ''math test'' - it''s a ''critical thinking test'' that requires lots of little calculations as you work through it. Most GMAT questions are designed so that they can be solved in more than one way (and certain Tactics ...” February 4, 2019 Rich.C@EMPOWERgmat.com posted a reply to In a certain sock drawer, there are 4 pairs of black socks, in the Problem Solving forum “Hi All, The concept in these types of questions is based on the ''worst case scenario'' - to guarantee that something will happen, you have to focus on the ''extreme/longest'' way that it could happen. Here, we have 4 black socks, 3 gray socks and 2 orange socks. The question asks for the ...” February 4, 2019 Rich.C@EMPOWERgmat.com posted a reply to The original price of a certain TV set is discounted by x in the Problem Solving forum “Hi All, We''re told that the original price of a certain TV set is discounted by X percent, the reduced price is then discounted by 2X percent and P is the original price of the TV set. We''re asked which of the following represents the price of the television set after the two successive ...” February 4, 2019 Brent@GMATPrepNow posted a reply to A committee of 6 is chosen from 8 men and 5 women so as to in the Problem Solving forum “Since the committee must have 6 people, there are two cases that meet the given restrictions: 1) The committee has 2 men and 4 women 2) The committee has 3 men and 3 women 1) The committee has 2 men and 4 women Since the order in which we select the men and women does not matter, we can use ...” February 4, 2019 Brent@GMATPrepNow posted a reply to Mixture problem unclear in the Problem Solving forum “When solving mixture questions, I find it useful to sketch the solutions with the ingredients SEPARATED. Since we''re asked to find a PERCENTAGE, we can assign a "nice" value to the original volume. So, let''s say we start with 100 liters https://i.imgur.com/yt2KAw7.png As you can ...” February 4, 2019 Brent@GMATPrepNow posted a reply to Mr. Jones spends$25 on movie tickets for a party of adults in the Data Sufficiency forum
“ Given: Mr. Jones spends $25 on movie tickets for a party of adults and children. Target question: How many children''s tickets did he buy? Statement 1: Adult movie tickets cost$3 each and children''s tickets cost $2 each. There are several scenarios that satisfy statement 1. Here are ...” February 4, 2019 Brent@GMATPrepNow posted a reply to In a certain sock drawer, there are 4 pairs of black socks, in the Problem Solving forum “If we remove 1 black sock, 1 gray sock, and 1 orange sock, then we still don''t have a matching sock. So, we can select 3 socks WITHOUT having a matching pair. However, if we pick ANY sock for our fourth sock, that sock MUST match one of the first 3 socks selected. Answer: A Cheers, Brent” February 4, 2019 Brent@GMATPrepNow posted a reply to Piper bought three shirts. The three shirts cost$210 in the Data Sufficiency forum
“IMPORTANT: Notice that statements 1 and 2 provide the EXACT SAME INFORMATION. When this occurs, the correct answer is either D or E Since the information is so sparse, I have a feeling that the correct answer is E. So, I''m going to try to find two possible cases that satisfy both statements, yet ...”
February 3, 2019
Brent@GMATPrepNow posted a reply to In the graduating class of a certain college, 48 percent of in the Problem Solving forum
“I thought I''d point out that Mitch''s Double Matrix Method approach can be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of students, and the two characteristics are: - male or female - younger than 25 ...”
February 3, 2019
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“Data Sufficiency lesson #3: Avoiding Common Mistakes - Part I Video : https://www.youtube.com/watch?v=iACq36scVYQ Cheers, Brent”
February 3, 2019
GMATGuruNY posted a reply to Bank Depositors (GMAT Prep) in the Critical Reasoning forum
“I received a PM requesting that I respond. Premise: Insurance removes from depositors any financial incentive to find out whether the bank that holds their money is secure against failure. Conclusion: The insurance is partly responsible for the high rate of bank failures. To determine the ...”
February 3, 2019
GMATGuruNY posted a reply to In the graduating class of a certain college, 48 percent of in the Problem Solving forum
“Every student is EITHER male OR female. Every student is EITER older OR younger. For an EITHER/OR problem, use a DOUBLE MATRIX to organize the data: _______________M______F_______Total older: younger: total: Let total students = 100: _______________M______F_______Total ...”
February 3, 2019
GMATGuruNY posted a reply to Kate and Danny each have $10. Together, they flip a fair coi in the Problem Solving forum “For every tails, Kate gets$1; for every heads, she loses $1. 0 tails, 5 heads: Kate has 10+0-5 =$5 1 tails, 4 heads: Kate has 10+1-4 = $7 2 tails, 3 heads: Kate has 10+2-3 =$9 3 tails, 2 heads: Kate has 10+3-2 = $11 4 tails, 1 heads: Kate has 10+4-1 =$13 5 tails, 0 heads: Kate has ...”
February 3, 2019
Rich.C@EMPOWERgmat.com posted a reply to The value of (10^8-10^2)/(10^7-10^3) is closest to which in the Problem Solving forum
“Hi All, We''re asked to choose the answer that is CLOSEST in value to (10^8-10^2)/(10^7-10^3). While you might be tempted to try lots of ''math steps'', if you consider how the answer choices are written, you can use a bit of estimation and logic to get to the correct answer without doing too ...”
February 2, 2019
Rich.C@EMPOWERgmat.com posted a reply to A company produces baseball cards in equal numbers of regula in the Problem Solving forum
“Hi All, We''re told that a company produces baseball cards in EQUAL numbers of regular packs of 16 and deluxe packs of 30. On a certain day, the company produces 241 cards. We''re asked for the SMALLEST number of additional cards the company needs to produce in order to maintain its regular ...”
February 2, 2019
Rich.C@EMPOWERgmat.com posted a reply to If the probability of rain on any given day is 50%, what is in the Problem Solving forum
“Hi All, We''re told that the probability of rain on any given day is 50%. We''re asked for the probability that it will rain on AT LEAST three days in a ROW during a five-day period. This question can be approached in a number of different ways; you might find it easiest to do a little math and ...”
February 2, 2019
Rich.C@EMPOWERgmat.com posted a reply to Father John forms a choir from the church attendants. in the Problem Solving forum
“Hi All, We''re told that Father John forms a choir from the church attendants. 30 people attend John''s church and the choir has 28 spots available, with one person as the lead singer. We''re asked for the number of different combinations for the choir. This question involves the Combination ...”
February 2, 2019
Rich.C@EMPOWERgmat.com posted a reply to A scriptwriter charges $4 for every standard script, which in the Problem Solving forum “Hi All, We''re told that a scriptwriter has a particular series of fees for a script (based on the length of the script). The scriptwriter charges.... 1)$4 for every standard script, which is 4 pages or shorter in length 2) 50 cents for every additional page 3) NO CHARGE for every 11th ...”
February 2, 2019
Brent@GMATPrepNow posted a reply to Beth has a collection of 8 boxes of clothing for a charity, in the Problem Solving forum
“One box contains 12 items of clothing Let t, u, v, w, x, y, z = the number of items in each of the other 7 boxes Beth has a collection of 8 boxes of clothing for a charity, and the average (arithmetic mean) number of pieces of clothing per box is c. We can write: (t + u + v + w + x + y + z + ...”
February 2, 2019
Rich.C@EMPOWERgmat.com posted a reply to A paint crew gets a rush order to paint 80 houses in a new d in the Problem Solving forum
“Hi All, We''re told that a paint crew gets a rush order to paint 80 houses in a new development. They paint the first Y houses at a rate of X houses per week. Realizing that they''ll be late at this rate, they bring in some more painters and paint the rest of the houses at the rate of 1.25X ...”
February 1, 2019
Rich.C@EMPOWERgmat.com posted a reply to Two-thirds of the roads from A to B are at least 5 miles in the Problem Solving forum
“Hi All, We''re told that 2/3 of the roads from A to B are at least 5 miles long, and 1/4 of the roads from B to C are at least 5 miles long. We''re asked to randomly pick a road from A to B and then randomly pick a road from B to C and determine the probability that AT LEAST ONE of the roads you ...”
February 1, 2019
Rich.C@EMPOWERgmat.com posted a reply to Is tutoring necessary for Verbal? in the GMAT Strategy forum
“Hi kyuhunl, The degree to which you might find tutoring useful will depend greatly on the study materials that you''re currently using and how quickly you can learn (and properly practice) certain concepts and Tactics. Before I can offer you the specific advice that you’re looking for, it ...”
February 1, 2019
Brent@GMATPrepNow posted a reply to Perpendicular lines m and n... in the Data Sufficiency forum
“ Given: Perpendicular lines m and n intersect at (0,b) Target question: What is the value of b? Statement 1: The slope of the line m is -1/2 Since line n is PERPENDICULAR to line m, we know that line n has slope 2 However, we can raise and lower the two lines so that the value of b is ...”
February 1, 2019
GMATGuruNY posted a reply to A paint crew gets a rush order to paint 80 houses in a new d in the Problem Solving forum
“Let y=0, implying that NONE of the 80 houses are painted at the original rate of x houses per week, with the result that ALL 80 houses are painted at the greater rate of (5/4)x houses per week. The total time it takes them to paint all the houses under this scenario is what fraction of the time ...”
February 1, 2019
GMATGuruNY posted a reply to Three pipes P, Q, and R are attached to a tank. P and Q indi in the Problem Solving forum
“Let the tank = 60 liters. Since P takes 3 hours to fill the 60-liter tank, P''s rate = 60/3 = 20 liters per hour. Since Q takes 4 hours to fill the 60-liter tank, Q''s rate = 60/4 = 15 liters per hour. Since R takes 5 hours to empty the 60-liter tank, R''s rate = -(60/5) = −12 liters per ...”
February 1, 2019
GMATGuruNY posted a reply to If ( x – y – 2 )^2 + ( x + z + 3 )^2 = 0, then what is t in the Problem Solving forum
“Let x=0. Plugging x=0 into (x-y-2)² + (x+z+3)² = 0, we get: (-y-2)² + (z+3)² = 0 Since neither (-y-2)² nor (z+3)² can be negative, the resulting equation is valid only if -y-2=0 and z+3=0, with the result that y=-2 and z=-3. Thus, y+z = -2 + (-3) = -5 The correct answer is E.”
February 1, 2019
Rich.C@EMPOWERgmat.com posted a reply to Suppose we have six marbles: 3 blue marbles, 2 red marbles, in the Problem Solving forum
“Hi All, We''re told that we have six marbles: 3 blue marbles, 2 red marbles, and one green marble - and that we are going to put them into three cups: a black cup, a white cup, and a purple cup. The only restriction is that the two red marbles CANNOT be in the same cup, meaning that we could put ...”
January 31, 2019
Rich.C@EMPOWERgmat.com posted a reply to During a two-week period, the price of an ounce of silver in the Problem Solving forum
“Hi All, We''re told that during a two-week period, the price of an ounce of silver INCREASED by 25 percent by the end of the first week and then DECREASED by 20 percent of this new price by the end of the second week. We''re asked, if the price of silver was X dollars per ounce at the beginning ...”
January 31, 2019
GMATGuruNY posted a reply to Cars J and K are making the trip from City A to City B. Car in the Problem Solving forum
“Since J catches up to K, J and K travel the same distance. Let t = J''s time. Since K leaves 15 minutes earlier than J, K''s time = t+15. Rate and time have a RECIPROCAL RELATIONSHIP. Since K''s rate is 80% of J''s rate, the ratio of K''s rate to J''s rate = 8/10 = 4/5. Thus, the ratio of ...”
January 31, 2019
GMATGuruNY posted a reply to f(2x-1) = ( x + 2 ) / ( x – 2 ). What is f(x)? in the Problem Solving forum
“Let x=1. Plugging x=1 into f(2x-1) = ( x + 2 ) / ( x – 2 ), we get: f(2*1 - 1) = (1+2)/(1-2) f(1) = -3. When x=1, the question stem becomes: What is f(1)? Since f(1) = -3, the correct answer must yield -3 when x=1. Only A works: f(1) = (1+5)/(1-3) = 6/-2 = -3. The correct answer is A.”
January 31, 2019
Rich.C@EMPOWERgmat.com posted a reply to A doctor prescribed 18 cubic centimeters of a certain drug t in the Problem Solving forum
“Hi All, This question is essentially about working through the necessary arithmetic. Thankfully, the math itself isn''t that tough, but you do have to stay organized to make sure that you''re setting up the proper calculations. We''re told that a typical dose of a drug is 2 cm^3 per 15 ...”
January 31, 2019
Rich.C@EMPOWERgmat.com posted a reply to A metal company's old machine makes bolts at a constant rate in the Problem Solving forum
“Hi All, The answer choices to this question provide a fantastic shortcut. With the two machines that we''re given, we know that... Old Machine = 100 bolts/hour New Machine = 150 bolts/hour If they start at the same time, the two machines will create 250 bolts/hour The question asks ...”
January 31, 2019
Rich.C@EMPOWERgmat.com posted a reply to A lecture course consists of 595 students. The students are in the Problem Solving forum
“Hi All, We''re told that a lecture course consists of 595 students and that the students are to be divided into discussion sections, each with an EQUAL number of students. We''re asked which of the following CANNOT be the number of students in a discussion section. This question is really just ...”
January 31, 2019
Rich.C@EMPOWERgmat.com posted a reply to What is the greatest prime factor of 3^6 - 1? in the Problem Solving forum
“Hi All, A number of the posts have provided elegant solutions to this question. The basic math behind this prompt is Arithmetic and Prime Factorization though, so if you don''t immediately "see" the elegant approach, you can still get to the answer.... We''re asked to find the ...”
January 31, 2019
GMATGuruNY posted a reply to A lecture course consists of 595 students. The students are in the Problem Solving forum
“(students per section)(number of sections) = 595 students number of sections = 595/(students per section). The equation in blue indicates that 595 must be divisible by the number of students per section. An integer is divisible by 3 only if its digit sum is a multiple of 3. The digit sum of ...”
January 30, 2019
GMATGuruNY posted a reply to Question about idioms and verbs in the Sentence Correction forum
“Correct: The contractors demolished the building to keep it from falling. Here, to keep is not an adjective modifying contractors but an ADVERB modifying demolished, expressing WHY the contractors DEMOLISHED the building. Question: WHY did the contractors demolish the building? Answer: TO KEEP it ...”
January 30, 2019
Brent@GMATPrepNow posted a reply to How many females? (GMAT Prep 2) in the Data Sufficiency forum
“Target question: What percent of the students in the class were females? Let''s use the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it (aka overlapping sets questions). Here, we have a ...”
January 30, 2019
GMATGuruNY posted a reply to DS work rate problem in the Data Sufficiency forum
“Statement 1: Case 1: Job = 12 units Since A and B together take 4 hours to complete the 12-unit job, the combined rate for A+B = 12/4 = 3 units per hour. Since A alone takes 6 hours to complete the 12-unit job, A''s rate alone = 12/6 = 2 units per hour. B''s rate = (combined rate for A+B) - ...”
January 30, 2019
GMATGuruNY posted a reply to PS arithmetic in the Problem Solving forum
“An alternate approach is to BALLPARK. √2 ≈ 1.4 √3 ≈ 1.7 (1+√3) * √(2 + √3) ≈ (2.7)(√3.7) = (2.7)(a bit less than 2) = a bit less than 5.4. When we evaluate the answer choices, only C is a bit less than 5.4: √2(2 + √3) ≈ (1.4)(3.7) = 5.18. The correct answer is C.”
January 30, 2019
Brent@GMATPrepNow posted a reply to A doctor prescribed 18 cubic centimeters of a certain drug t in the Problem Solving forum
“We can use equivalent ratios to determine what the dosage SHOULD have been. We''ll use the ratio of drug dosage (in cubic centimeters)/body weight (in pounds) Let x = the dosage (in cubic centimeters) the patient SHOULD have received We get: 2/15 = x/120 Cross multiply to get: 15x = ...”
January 30, 2019
GMATGuruNY posted a reply to DS arithmetic in the Data Sufficiency forum
“Statement 1: The inequality implies that a is POSITIVE, allowing us to cross-multiply: 1*2 > a*1 2 > a Since 2>a and a>b>0, we get: 2>a>b>0 Thus, b<2. SUFFICIENT. Statement 2: If b=2, we get: 1/a + 1/2 = 1 1/a = 1/2 a=2 Not possible, since the prompt ...”
January 30, 2019
GMATGuruNY posted a reply to The sum of 4 different odd integers is 64. in the Data Sufficiency forum
“Statement 1: Since the numbers are EVENLY SPACED, median = sum/count: 64/4 = 16. Since the median = 16, the 4 odd integers must be as follows: 13, 15, 17, 19. Thus, the greatest of the 4 odd integers = 19. SUFFICENT. Statement 2: The 4 odd integers yielded by Statement 1 -- 13, 15, ...”
January 30, 2019
Brent@GMATPrepNow posted a reply to Marla starts running around a circular track at the same... in the Problem Solving forum
“Let t = the time (in HOURS) that it takes Marla to complete 4 more laps than Nick. So, after t hours, we can write: (Marla''s lap count) = (Nick''s lap count) + 4 Now that we have a "word equation" we need only fill in the missing information Marla completes 32 laps per hour We can ...”
January 29, 2019
GMATGuruNY posted a reply to To create a part for a certain piece of machinery, four equa in the Problem Solving forum
“The four 18-degree shaded regions = 4*18 = 72 degrees. The entire circle = 360 degrees. (shaded regions)/(entire circle) = 72/360 = 1/5. Thus: (unshaded regions)/(entire circle) = 1 - 1/5 = 4/5 = 80%. The correct answer is E.”
January 29, 2019
Brent@GMATPrepNow posted a reply to Paul, a painter, paints only flowers or cats in his notebook in the Data Sufficiency forum
“I thought I''d point out that the approach demonstrated by Fabio and Jay is known as the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of paintings, and the ...”
January 29, 2019
Brent@GMATPrepNow posted a reply to f(x) has the properties, f(x+y) = x + f(y) and f(0) = 5. Wha in the Problem Solving forum
“Given: f(x+y) = x + f(y) What is the value of f(100)? We need to somehow use the fact that f(0) = 5 to help us determine the value of f(100). Notice that we can rewrite 100 as 100 + 0 According to our the function f, we know that: f(100 + 0) = 100 + f(0) = 100 + 5 = 105 Answer: C ...”
January 29, 2019
Brent@GMATPrepNow posted a reply to Leila is playing a carnival game in which she is given 4 in the Problem Solving forum
“Given: P(succeeds on 1 throw) = 1/5 P(succeeds at least 3 times) = P(succeeds 4 times OR succeeds 3 times) = P(succeeds 4 times) + P(succeeds 3 times) P(succeeds 4 times) P(succeeds 4 times) = P(succeeds 1st time AND succeeds 2nd time AND succeeds 3rd time AND succeeds 4th time) = ...”
January 29, 2019
Brent@GMATPrepNow posted a reply to A waitress's income consist of her salary and tips. During in the Problem Solving forum
“APPROACH #1 - start with a convenient value of the server''s salary Let''s say her salary is $4 GIVEN: her tips were 5/4 of her salary 5/4 of$4 = $5 So, her tip total was$5 What fraction of her income for the week came from tips? Income = salary + tips = $4 +$5 = $9 Fraction =$5 /$9 ...” January 29, 2019 Brent@GMATPrepNow posted a reply to To create a part for a certain piece of machinery, four equa in the Problem Solving forum “IMPORTANT: the diagrams in GMAT problem solving questions are DRAWN TO SCALE unless stated otherwise. We can use this fact to solve the question by simply "eyeballing" the diagram. The question is basically asking us to determine what percent of the circle is NOT shaded. Well, ...” January 29, 2019 Brent@GMATPrepNow posted a reply to If (x+y)/z = -2, is x positive? in the Data Sufficiency forum “Target question: Is x positive? Given: (x + y)/z = -2 Since the question asks about the variable x, let''s solve this equation for x. (x + y)/z = -2 So, x + y = -2z And, x = -2z - y This allows us to REPHRASE the target question.... REPHRASED target question: Is -2z - y positive? ...” January 29, 2019 Rich.C@EMPOWERgmat.com posted a reply to A new tower has just been built at the Verbico military in the Problem Solving forum “Hi j_shreyans, I''m a big fan of TESTing Values (Mitch''s explanation), but this question can also be solved with algebra…. We''re told that adding a new tower to an existing hospital allows fore 3 times the number of available beds that were there before the tower was built: Just the ...” January 28, 2019 Rich.C@EMPOWERgmat.com posted a reply to A certain company has 18 equally qualified applicants for 4 in the Problem Solving forum “Hi All, We''re told that a certain company has 18 equally qualified applicants for 4 open positions. We''re asked for the number of different groups of 4 applicants that can be chosen by the company to fill the positions if the order of selection does not matter. This question is a fairly ...” January 28, 2019 Rich.C@EMPOWERgmat.com posted a reply to When 12 marbles are added to a rectangular aquarium, the wat in the Problem Solving forum “Hi All, We''re told that when 12 marbles are added to a rectangular aquarium, the water in the aquarium rises 1 1/2 inches. We''re asked how many marbles must be added to the aquarium in total to raise the water 2 3/4 inches. This question is ultimately about ratios, so you can approach the math ...” January 28, 2019 Brent@GMATPrepNow posted a reply to The table above shows the GPA of 20 students last semester. in the Problem Solving forum “---------------ASIDE-------------- A little extra background on standard deviations above and below the mean If, for example, a set has a standard deviation of 4, then: 1 standard deviation = 4 2 standard deviations = 8 3 standard deviations = 12 1.5 standard deviations = 6 0.25 ...” January 28, 2019 GMATGuruNY posted a reply to When 12 marbles are added to a rectangular aquarium, the wat in the Problem Solving forum “The desired height increase = 11/4 inches. 12 marbles yield a height increase of 3/2 inches. Thus: (desired height increase of 11/4 inches) * (12 marbles)/(height increase of 3/2 inches) = (11/4 * 12)/(3/2) = 33/(3/2) = (33*2)/3 = 11*2 = 22 marbles. The correct answer is D.” January 28, 2019 GMATGuruNY posted a reply to A certain company has 18 equally qualified applicants for 4 in the Problem Solving forum “From 18 applicants, the number of ways to choose 4 = 18C4 = (18*17*16*15)/(4*3*2*1) = (3*17*4*15) = 51*60 = 3060. The correct answer is E.” January 28, 2019 GMATGuruNY posted a reply to A new tower has just been built at the Verbico military in the Problem Solving forum “Let the PRE-TOWER number of beds = the LCM of the denominators in the problem = 3*5 = 15. Then the CURRENT number of beds = 3*15 = 45, implying that the number of beds in the NEW tower = 45-15 = 30. Occupied beds = (1/3)15 + (1/5)30 = 11. Non-occupied beds in the new tower = 30-11 = 19. ...” January 28, 2019 Brent@GMATPrepNow posted a reply to A dental licensure exam requires a 75% minimum score in orde in the Data Sufficiency forum “ Given: A dental licensure exam requires a 75% minimum score in order to pass each section Target question: Did Jennifer pass the 30-question third section? 75% of 30 = 22.5 So, in order to get at least 75% in the 3rd section, Jennifer must correctly answer 23 or more questions in the 3rd ...” January 28, 2019 Rich.C@EMPOWERgmat.com posted a reply to A certain library assesses fines for overdue books as in the Problem Solving forum “Hi ALL, This question includes a ''conditional statement'' that effects how you''re supposed to handle each "step" in the math: "for each additional day....., the total fine is EITHER increased by 30 cents OR doubled, whichever results in the LESSER AMOUNT." Since ...” January 27, 2019 Rich.C@EMPOWERgmat.com posted a reply to Machines A and B, working together, take t minutes to in the Problem Solving forum “Hi All, We''re told that Machines A and B, working together, take T minutes to complete a particular work. Machine A, working alone, takes 64 minutes more than T to complete the same work. Machine B, working alone, takes 25 minutes more than T to complete the same work. We''re asked for the ...” January 27, 2019 GMATGuruNY posted a reply to Machines A and B, working together, take t minutes to in the Problem Solving forum “One more approach: Since A+B together complete the job in t minutes: Job = (A''s output in t minutes) + (B''s output in t minutes) If A works alone for t minutes, A can then complete the rest of the job in 64 minutes. In this case, the rest of the job = B''s output in t minutes. Thus, A''s ...” January 27, 2019 Brent@GMATPrepNow posted a reply to Barbara invests$2400 in the National Bank at 5%. How much in the Problem Solving forum
“Barbara invests $2400 in the National Bank at 5%. So, her annual income for this investment = 5% of$2400 = $120 Let x = the additional money Barbara must invest at 8% So, her annual income for this investment = 8% of x = 0.08x So, Barbara''s TOTAL annual income =$120 + 0.08x We want the ...”
January 27, 2019
Brent@GMATPrepNow posted a reply to A certain library assesses fines for overdue books as in the Problem Solving forum
“1st day - $0.10 2nd day -$0.20 or $0.40 (double or add$0.30) $0.20 is the lesser amount 3rd day -$0.40 or $0.50 (double or add$0.30) $0.40 is the lesser amount 4th day -$0.80 or $0.70 (double or add$0.30) $0.70 is the lesser amount The correct answer is B Cheers, Brent” January 27, 2019 GMATGuruNY posted a reply to Prompted by observations of seemingly related species in the Sentence Correction forum “A present perfect verb (has + VERBed or have + VERBed) expresses a PAST ACTION that affects the present. Generally, the usage of a present perfect verb implies that the subject of the verb still exists. Incorrect: The dinosaurs have evolved over time. The sentence above is illogical because the ...” January 27, 2019 GMATGuruNY posted a reply to Machines A and B, working together, take t minutes to in the Problem Solving forum “Always keep your eye on the answer choices. Since A''s time alone (t+64) is greater than B''s time alone (t+25), the ratio of A''s time alone to B''s time alone must be GREATER THAN 1. Eliminate A, C and D. Since the ratio of A''s time to B''s time = (t+64)/(t+25), option E implies the ...” January 27, 2019 GMATGuruNY posted a reply to A certain library assesses fines for overdue books as in the Problem Solving forum “First day: Total fine = 10. For each additional day, the total fine either increases by 30 or doubles -- whichever results in a lesser amount. Second day: Adding 30 cents to the 1-day fine, we get 10+30 = 40. Doubling the 1-day fine, we get 2*10 = 20. Total fine = lesser amount = 20. ...” January 27, 2019 Rich.C@EMPOWERgmat.com posted a reply to When 12 marbles are added to a rectangular aquarium, the in the Problem Solving forum “Hi All, We''re told that when 12 marbles are added to a rectangular aquarium, the water in the aquarium rises 1 1/2 inches. We''re asked how many marbles must be added to the aquarium in total to raise the water 2 3/4 inches. This question is ultimately about ratios, so you can approach the math ...” January 26, 2019 Rich.C@EMPOWERgmat.com posted a reply to Barbara invests$2400 in the National Bank at 5%. How much in the Problem Solving forum
“Hi All, We''re told that Barbara invests $2400 in the National Bank at 5%. We''re asked how much additional money she must invest at 8% so that the TOTAL annual income will be equal to 6% of her entire investment. This question can be approached in a number of different ways, including by ...” January 26, 2019 Brent@GMATPrepNow posted a reply to Probability/ combination in the Problem Solving forum “P(Tamara and Inga are BOTH chosen for the jury) = (# of ways to choose 7 people that include Tamara and Inga)/(TOTAL # of ways to choose 7 people) # of ways to choose 7 people that include Tamara and Inga Stage 1: place Tamara and Inga on the jury. This can be accomplished in 1 way Stage 2: ...” January 26, 2019 GMATGuruNY posted a reply to If the drama club and music club are combined, what percent in the Data Sufficiency forum “Clearly, neither statement alone is sufficient. Statements combined: Case 1: No one is a member of both clubs Total males = 15+10 = 25. Total members = 16+20 = 36. Resulting fraction: (total males)/(total members) = 25/36. Case 2: Every male in the music club is also in the drama ...” January 26, 2019 GMATGuruNY posted a reply to Frank and Georgia started traveling from A to B at the same in the Problem Solving forum “Let d = the number of miles between A and B. Since Georgia travels the entire d miles between A and B and then an additional 60 miles back toward A, Georgia''s distance = d+60. Since Frank travels all but 60 of the d miles between A and B, Frank''s distance = d-60. Since Georgia''s travels 3/2 ...” January 26, 2019 Brent@GMATPrepNow posted a reply to A sports team played 100 games last season. Did this team in the Data Sufficiency forum “Target question: Did this team win at least half of the games it played last season? Rephrased target question: Did this team win more than 49 games? Statement 1: The team won 60% of its first 65 games In other words, the team won 39 of its first 65 games Since we don''t know the results ...” January 26, 2019 Rich.C@EMPOWERgmat.com posted a reply to Ratio in the Problem Solving forum “Hi All, We''re told that a in the first M games of a team´s season, the ratio of the team´s wins to its losses was 1:2 and in the subsequent N games, the ratio of the team´s wins to losses was 1:3. If M:N = 4:5, we''re asked for the ratio of the team´s wins to its losses for all M+N games. ...” January 25, 2019 Rich.C@EMPOWERgmat.com posted a reply to A major airplane manufacturer announced the sale of 150 in the Problem Solving forum “Hi All, We''re told that a major airplane manufacturer announced the sale of 150 small airliners at$125 million each, 75 medium sized airliners at $175 million each, and 60 large airliners at$220 million each. We''re asked for the percentage of the company''s income that came from large and ...”
January 25, 2019
GMATGuruNY posted a reply to Ratio in the Problem Solving forum
“Let S = the entire season (in other words, the mixture of M and N). Alligation can be performed only with percentages or fractions. Step 1: Convert the ratios to FRACTIONS. M: Since win:losses = 1:2, and 1+2=3, wins/total = 1/3. N: Since wins:losses = 1:3, and 1+3=4, wins/total = 1/4. ...”
January 25, 2019
Brent@GMATPrepNow posted a reply to If 2 roots of the equation x^2+px+q=0 are -3 and 2, what is in the Problem Solving forum
“GIVEN: the roots/solutions are x = -3 and x = 2 Notice that x = -3 and x = 2 are solutions to the equation (x + 3)(x - 2) = 0 If we expand and simplify the left side of the equation, we get: x² + x - 6 = 0 So, the equation x² + x - 6 = 0 has roots -3 and 2 Compare this to x² + px + q = 0 to ...”
January 25, 2019
Brent@GMATPrepNow posted a reply to The numbers m, n, and K are all positive integers. Given tha in the Problem Solving forum
“Different approach: The question asks "which of the following must also be a positive integer factor of K?" So, if we can find an answer choice that is NOT a factor of K we can ELIMINATE that answer choice. A. m + n If K = 12, then if COULD be the case that m = 4 and n = 6 In ...”
January 25, 2019
Brent@GMATPrepNow posted a reply to The numbers m, n, and K are all positive integers. Given tha in the Problem Solving forum
“GIVEN: m is a factor of K This means that we can write: K = md for some integer d If m and d are both integers, then m and d are both factors of K Notice that, if K = md, then d = K/m, which means K/m is a factor of K Answer: D Cheers, Brent”
January 25, 2019
Brent@GMATPrepNow posted a reply to If, J, K, L, M, and N are positive integers in ascending ord in the Data Sufficiency forum
“ Given: J, K, L, M, and N are positive integers in ascending order Target question: What is the value of L? Statement 1: The value of K is 3. There are many scenarios that satisfy statement 1. Here are two: Case a: J = 1, K = 3, L = 4, M = 7, N = 8. In this case, the answer to the ...”
January 25, 2019
GMATGuruNY posted a reply to How many factors greater than 1 do 120, 210, and 270 have in in the Problem Solving forum
“120 = 30*4 210 = 30*7 270 = 30*9 The GCF = the value in blue = 30. Factors of 30 greater than 1: 2, 3, 5, 6, 10, 15, 30 --> 7 factors Thus, 120, 210, and 270 have 7 common factors greater than 1. The correct answer is D.”
January 24, 2019
GMATGuruNY posted a reply to Stacy and Katie plan to walk the 27-mile scenic route across in the Problem Solving forum
“Since Stacy and Katie travel toward each other, they WORK TOGETHER to cover the 27 miles between them. Since Stacy is 1/4 faster than Katie, for every 4 miles that Katie travels, the distance traveled by Stacy = 4 + (1/4)(4) = 5 miles. Thus, of every 9 miles traveled when Stacy and Katie work ...”
January 24, 2019
Brent@GMATPrepNow posted a reply to Mary and Kate are running clockwise around a circular track in the Problem Solving forum
“To get a better idea of what''s happening, let''s sketch the set-up: https://i.imgur.com/SwHzFJD.png Mary is faster than Kate, we can say that Kate has a 250 meter head start. In other words, when Mary closes that 250-meter gap, she will pass Kate for the FIRST time. ...”
January 24, 2019
Rich.C@EMPOWERgmat.com posted a reply to A miniature roulette wheel is divided into 10 equal sectors, in the Problem Solving forum
“Hi All, We''re told that a miniature roulette wheel is divided into 10 equal sectors, each bearing a distinct integer from 1 to 10, inclusive. Each time the wheel is spun, a ball randomly determines the winning sector by settling in that sector and the wheel is spun three times. We''re asked for ...”
January 24, 2019
Rich.C@EMPOWERgmat.com posted a reply to The total cost of a vacation was divided among 3 people. If in the Problem Solving forum
“Hi All, We''re told that the total cost of a vacation was divided equally among 3 people and that if the total cost of the vacation had been divided equally among 4 people, then the cost per person would have been $50 LESS. We''re asked for the total cost of the vacation. This question can be ...” January 24, 2019 Rich.C@EMPOWERgmat.com posted a reply to A shirt that costs k dollars is increased by 30%, then by an in the Problem Solving forum “Hi All, We''re told that the price of a shirt that costs K dollars is increased by 30%, then that price is increased by an additional 50%. We''re asked for the final price of the shirt in dollars, in terms of K. This question can be solved in a number of different ways - including Algebraically ...” January 24, 2019 Brent@GMATPrepNow posted a reply to In the rectangular coordinate system above, the area of tria in the Problem Solving forum “Let''s draw a rectangle around the triangle (as shown below) and then subtract from the rectangle''s area (28) the areas of the 3 right triangles that surround the triangle in question. We get the following: http://s13.postimage.org/a47qx0j8j/triangle_in_coordinate_plane_2.jpg So, the area ...” January 24, 2019 Brent@GMATPrepNow posted a reply to A shirt that costs k dollars is increased by 30%, then by an in the Problem Solving forum “A shirt that costs k dollars is increased by 30%, So, the new coast = k + (30% of k) = k + 0.3k = 1.3k ASIDE So, increasing a value by 30% is the same as multiplying that value by 1.3 Similarly, increasing a value by 20% is the same as multiplying that value by 1.2 And increasing a value by ...” January 24, 2019 Brent@GMATPrepNow posted a reply to The total cost of a vacation was divided among 3 people. If in the Problem Solving forum “Let T = total cost of vacation So, T/3 = cost per person with THREE people And T/4 = cost per person with FOUR people If the total cost of the vacation had been divided equally among 4 people, the cost per person would have been$50 less. In other words (cost per person with FOUR people) = ...”
January 24, 2019
Rich.C@EMPOWERgmat.com posted a reply to Getting out of a Rut: Overcoming 680 over 3 consecutive atte in the I just Beat The GMAT! forum
“Hi markymarc89, That''s OUTSTANDING news! With a 740/Q50, you can comfortably apply to ANY Business Schools that interest you. Since you''ve already taken care of your applications, there''s not much else to do at this point (unless you want to consider applying to any additional Schools). We''re ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to A restaurant meal cost $35.50 and there was no tax. If the t in the Problem Solving forum “Let''s first see what happens when the tip is 10% 10% of$35.50 = $3.55 So, the total cost (WITH a 10% tip) =$35.50 + $3.55 =$39.05 So, the total cost must be GREATER THAN $39.05 This means the TOTAL cost could be$39.06 Check the answer choices.... A, D and E do not allow for the total cost ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to If i, a and b are integers, is 4(3b + 2) = 5a? (1) If i is in the Data Sufficiency forum
“Target question: Is 4(3b + 2) = 5a? Statement 1: If i is divided by 5 the quotient is a and the remainder is 3 ASIDE: There''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 divided by 5 equals 3 with remainder 2, then we ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to If the average of four numbers is 35, how many of the number in the Data Sufficiency forum
“ Given: The average of four numbers is 35 Target question: How many of the numbers are less than 35? If we''re able to see that the statements FEEL insufficient, and we''re able to come up with some counter-examples in our head, then we can head straight to... . . . Statements 1 and 2 ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to If x is a positive integer, is x<16? 1) x is less than t in the Data Sufficiency forum
“Target question: Is x < 16? Statement 1: x is less than the average (arithmetic mean) of the first ten positive integers Since the first ten positive integers are EQUALLY SPACED, the average = (smallest number + biggest number)/2 = (1 + 10)/2 = 5.5 So, x < 5.5 Since 5.5 < 16, we ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to What is the measure of each interior angle of a regular deca in the Problem Solving forum
“Useful rule: the sum of the angles in an n-sided polygon = (n - 2)(180º) So, for example, the sum of the angles in an 11-sided polygon = (11 - 2)(180º) = (9)(180º) = 1620º What is the measure of each interior angle of a regular decagon? A decagon has 10 sides. The sum of the angles in ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to x=? in the Data Sufficiency forum
“Target question: What is the value of x? Statement 1: x³ - x = 0 Factor to get: x(x² - 1) = 0 Factor again to get: x(x + 1)(x - 1) = 0 So, it could be the case that x = 0, x = -1 or x = 1 Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to Ayayai electronics is a company manufacturing MP3 players. in the Problem Solving forum
“I thought I''d point out that Jay''s approach is known as the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of MP3 players, and the two characteristics are: ...”
January 23, 2019
Brent@GMATPrepNow posted a reply to If when a certain integer x is divided by 5, the remainder in the Problem Solving forum
“Here''s another (longer) approach: When it comes to remainders, we have a nice rule that says: If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc. For example, if k divided by 5 leaves a remainder of 1, then the possible values of k ...”
January 22, 2019
Brent@GMATPrepNow posted a reply to If Polygon X has fewer than 9 sides, how many sides does in the Data Sufficiency forum
“Target question: How many sides does Polygon X have? Given: Polygon X has fewer than 9 sides Useful rule: The sum of the angles in an n-sided polygon = (n - 2)(180º) Since the polygon has FEWER than 9 sides, there are are exactly SIX possible cases: case a: There are 8 sides, in ...”
January 22, 2019
GMATGuruNY posted a reply to If when a certain integer x is divided by 5, the remainder in the Problem Solving forum
“Since dividing x by 5 yields a remainder, x is not a multiple of 5 and thus not a multiple of 10. Since x is not a multiple of 10, x/10 cannot yield an integer value. The correct answer is B.”
January 22, 2019
GMATGuruNY posted a reply to Mary and Kate are running clockwise around a circular track in the Problem Solving forum
“Since Mary is behind Kate by 250 meters -- half the circumference of the track -- she will catch up to Mary when she has traveled 250 meters more than Kate. To catch up to Kate a second time, Mary must then travel one more lap than Kate -- in other words, 500 meters more than Kate. Implication: ...”
January 22, 2019
Rich.C@EMPOWERgmat.com posted a reply to Of the votes cast on a certain proposal, 80 more were in in the Problem Solving forum
“Hi All, We''re told that of the votes cast on a certain proposal, 80 MORE were in favor of the proposal than were against it and the number of votes against the proposal was 40 percent of the TOTAL vote. We''re asked for the total number of votes cast? (Each vote cast was either in favor of the ...”
January 22, 2019
Rich.C@EMPOWERgmat.com posted a reply to Which of the following is closest to the value of (2^23) in the Problem Solving forum
“Hi All, We''re asked which of the following is closest to the value of (2^23)(5^26). If you don''t immediately see the ''Exponent'' rules that apply to this question, then you can still solve it with some basic Arithmetic and logic. To start, when you multiply a bunch of numbers together, the ...”
January 22, 2019
Rich.C@EMPOWERgmat.com posted a reply to The number 75 can be written as the sum of the squares of 3 in the Problem Solving forum
“Hi All, This question can be solved with a bit of ''brute force'' arithmetic, but the speed with which you solve it will likely depend on how quickly you can write everything down and how you do the work. We''re asked to find the three positive integers, whose squares add up to 75. To start, ...”
January 22, 2019
Brent@GMATPrepNow posted a reply to The number 75 can be written as the sum of the squares of 3 in the Problem Solving forum
“We''re looking for 3 DIFFERENT squares that add to 75 Here are the only squares we need to consider: 1, 4, 9, 16, 25, 36, 49, 64 Can you find 3 that add to 75? After some fiddling, we may notice that 1 + 25 + 49 In other words, 1² + 5² + 7² = 75 We want the SUM of 1 + 5 + 7, which is ...”
January 22, 2019
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“Data Sufficiency Video #2: The Elimination Method Video: https://www.youtube.com/watch?v=amhxP9My_pU Cheers, Brent”
January 22, 2019
GMATGuruNY posted a reply to If y=|x-1|+|x+1|, then y=? in the Data Sufficiency forum
“|x-1| = the distance between x and 1. |x+1| = the distance between x and -1. -1<--|x+1|-->x<--|x-1|-->1 Here, since the total distance between the two endpoints is 2, the sum of the 2 distances in red is 2. If x is any value between the two endpoints, then the sum of the two ...”
January 22, 2019
GMATGuruNY posted a reply to A = (2-3+4)^{11}, and B = (-2+3-4)^{11}. What is the value o in the Problem Solving forum
“A = (2-3+4)¹¹ = 3¹¹ B = (-2+3-4)¹¹ = (-3)¹¹ = -3¹¹ Thus: A+B = 3¹¹ - 3¹¹ = 0 2^(A+B) = 2⁰ = 1. The correct answer is C.”
January 22, 2019
GMATGuruNY posted a reply to GMAT OG 2019 The Commerce Department reported that in the Sentence Correction forum
“were + VERBing is the plural form of the PAST PROGRESSIVE tense (also known as the past continuous tense). The past progressive tenses serve to express actions that happen CONTINUOUSLY FOR A LIMITED DURATION OF TIME. OA: While businesses were expanding their production, unsold goods were piling ...”
January 22, 2019
GMATGuruNY posted a reply to Machine A produces pencils at a constant rate of 9000 in the Problem Solving forum
“To minimize B''s time, we must maximize A''s time. Since each machine can work for at most 8 hours, let A''s time = 8 hours. Since A''s rate = 9000 pencils per hour, the number of pencils produced by A in 8 hours = rt = 9000*8 = 72,000. Remaining pencils = 100,000 - 72,000, = 28,000. Since ...”
January 21, 2019
Brent@GMATPrepNow posted a reply to The average salary of 15 people in the shipping department in the Problem Solving forum
“]The average salary of 15 people in the shipping department at a certain firm is $20,000 So, (sum of all 15 salaries)/15 =$20,000 Multiply both sides by 15 to get: sum of all 15 salaries = $300,000 The salary of 5 of the employees is$25,000 each and the salary of 4 of the employees is $16,000 ...” January 21, 2019 GMATGuruNY posted a reply to A bowl contains pecans, cashews, and almonds in a ratio of 6 in the Problem Solving forum “Original ratio values: P.................................................C...............................................A 6x<---distance of 4x--->10x<---distance of 5x--->15x Options for the new ratio: I) 1 : 2 : 3 I) 2 : 3 : 4 III) 4 : 7 : 10 The ratio values in each ...” January 21, 2019 Brent@GMATPrepNow posted a reply to A triangle has side lengths of a, b, and c centimeters. in the GMAT Math forum “Target question: Does each angle in the triangle measure less than 90 degrees? Given: A triangle has side lengths of a, b, and c centimeters Statement 1: The 3 semicircles whose diameters are the sides of the triangle have areas that are equal to 3 cm², 4 cm², and 6 cm², respectively. ...” January 21, 2019 Brent@GMATPrepNow posted a reply to If x-2y=4, then x^2-4xy+4y^2-x+2y=? in the Problem Solving forum “GIVEN: x - 2y = 4 We want to find the value of x² - 4xy + 4y² - x + 2y We should notice that x² - 4xy + 4y² is equal to (x - 2y)² We should notice that - x + 2y is equal to -(x - 2y) We get: x² - 4xy + 4y² - x + 2y = (x - 2y)² - (x - 2y) Now replace x - 2y with 4 to get: = (x - ...” January 21, 2019 Brent@GMATPrepNow posted a reply to What is the value of z in the triangle above? (1) x+y=139 ( in the Data Sufficiency forum “Target question: What is the value of z in the triangle above? IMPORTANT: Since angles in a triangle must add to 180 degrees, we can write: x + y + z = 180 Statement 1: x + y = 139 Take: x + y + z = 180 and replace (x + y) with 139 to get: 139 + z = 180 Solve equation for z to get: z = 41 ...” January 21, 2019 Brent@GMATPrepNow posted a reply to 10 different biology books and 8 different chemistry books l in the Problem Solving forum “Take the task of selecting 4 books and break it into stages. Stage 1: Select two biology books Since the order in which we select the books does not matter, we can use combinations. We can select 2 books from 10 books in 10C2 ways (45 ways) So, we can complete stage 1 in 45 ways If ...” January 21, 2019 Brent@GMATPrepNow posted a reply to What was the number of defective batteries in a shipment of in the Data Sufficiency forum “Target question: What was the number of defective batteries in a shipment of 4000 batteries? Statement 1: In a particular sample of 10 batteries selected from the shipment, 1 was defective. Don''t make the mistake of assuming that this means 1/10 of ALL batteries are defective. There''s no ...” January 21, 2019 GMATGuruNY posted a reply to If x-2y=4, then x^2-4xy+4y^2-x+2y=? in the Problem Solving forum “Let x=4 and y=0, with the result that x-2y = 4. Plugging x=4 and y=0 into x² - 4xy + 4y² - x + 2y, we get: 4² - 0 + 0 - 4 + 0 = 12. The correct answer is A.” January 21, 2019 Rich.C@EMPOWERgmat.com posted a reply to If Sam were twice as old as he is, he would be 40 years in the Problem Solving forum “Hi All, We''re told that if Sam were TWICE as old as he is, then he would be 40 years older than Jim and that Jim is currently 10 years YOUNGER than Sam. We''re asked for Sam''s current age. This question can be solved in a couple of different ways, including by TESTing THE ANSWERS. Since the ...” January 20, 2019 Rich.C@EMPOWERgmat.com posted a reply to [x] denotes the least integer greater than or equal to x ... in the Problem Solving forum “Hi All, This is an example of a ''Symbolism'' question - the prompt ''makes up'' a math symbol, tells you what it means, then asks you to perform a calculation using it. When dealing with these types of symbols, it often helps to jot down a few examples, so that you understand the work that will ...” January 20, 2019 Rich.C@EMPOWERgmat.com posted a reply to On a game show, a contestant is given three keys, each of in the Problem Solving forum “Hi All, We''re told that on a game show, a contestant is given three keys, each which opens exactly one of three identical boxes. The first box contains$1, the second $100, and the third$1000. The contestant assigns each key to one of the boxes and wins the amount of money contained in any box ...”
January 20, 2019
Brent@GMATPrepNow posted a reply to On a game show, a contestant is given three keys, each of in the Problem Solving forum
“There aren''t many possible outcomes, so let''s start by listing all possibilities. Let A, B and C represent the 3 boxes, and let a, b, c, be the keys for those boxes (in that same order). A = $1 prize, B =$100 prize and C = $1000 prize If the boxes are arranged as A-B-C, then these are ...” January 20, 2019 Brent@GMATPrepNow posted a reply to Which of the following lists a number of points at which a in the Problem Solving forum “http://s27.postimg.cc/531tmnqpr/circ_int.jpg Answer: E The important takeaway here is that "intersect" does not necessarily mean "pass through" So, a line that is tangent to a circle (touching the circle but not passing through it) can be said to intersect the circle. To ...” January 20, 2019 Brent@GMATPrepNow posted a reply to [x] denotes the least integer greater than or equal to x ... in the Problem Solving forum “First, let''s take a moment to get a good idea of what this strange notation means. A few examples: -1 < x/2 ≤ 0 Multiply all sides of the inequality by 2 to get: -2 < x ≤ 0 Check the answer choices.... Only -3/2 falls inside that range. Answer: B Cheers, Brent” January 20, 2019 Brent@GMATPrepNow posted a reply to Full Plan in the The 60-Day GMAT Study Guide forum “Hi Aliya, I have a feeling that your email system is treating the emails as spam. Have you checked your spam/junk folders? You might to sign up for the emails again, but this time, be sure to add guide@beatthegmat.com as a contact in your e-mail system. This will help ensure that the daily ...” January 20, 2019 Brent@GMATPrepNow posted a reply to The average American spends y dollars on food per month, exc in the Problem Solving forum “This is a Variables in the Answer Choices question (VIAC). This question type can be answered algebraically or using the INPUT-OUTPUT approach. Mitch has demonstrated the INPUT-OUTPUT approach, so let''s solve the question algebraically. The average American spends y dollars on food per month, ...” January 20, 2019 GMATGuruNY posted a reply to A company bought some desks at a price of$150 each and some in the Data Sufficiency forum
“Test the THRESHOLD. In the question stem, the threshold is 40 CHAIRS. The total cost of 40 chairs = 40*50 = 2000. Statement 1: The total price of the desks and chairs is 5,000. It is possible that 40 chairs are purchased (at a total cost of $2000) or that MORE CHAIRS are purchased. ...” January 20, 2019 GMATGuruNY posted a reply to What is the value of x? in the Data Sufficiency forum “Statement 1: To have exactly 3 positive factors, x must be the square of a prime number. Factors of x=2²=4: 1, 2, 4 Factors of x=3²=9: 1, 3, 9 Factors of x=5²=25: 1, 5, 25. Since x can be different values, INSUFFICIENT. Statement 2: Clearly INSUFFICIENT. Statements combined: x ...” January 20, 2019 GMATGuruNY posted a reply to The average American spends y dollars on food per month, exc in the Problem Solving forum “Monthly food expense except in January: Let y=$2. Discount in January: Let x=100%. Since $2 is spent each month for 8 of the first 9 months, the total spent during these 8 months = 8*2 = 16. Since food purchases are 100% lower in January -- implying that they are FREE in January -- the amount ...” January 20, 2019 Brent@GMATPrepNow posted a reply to If a is a positive integer and 81 divided by a in the Data Sufficiency forum “Target question: What is the value of a? Given: 81 divided by a results in a remainder of 1 In other words, 81 is 1 greater than some multiple of a This means that 80 is some multiple of a Another way to say this is: a is a divisor of 80 The divisors of 80 are: 1, 2, 4, 5, 8, 10, 16, ...” January 19, 2019 Brent@GMATPrepNow posted a reply to Set A = {2, 3, 4, 5}, and set B = {4, 5, 6, 7, 8}. If P = th in the Problem Solving forum “Let''s list and count all possible outcomes. Possible products when 2 is selected from set A: 8, 10, 12, 14, 16 Possible products when 3 is selected from set A: 12, 15, 18, 21, 24 Possible products when 4 is selected from set A: 16, 20, 24, 28, 32 Possible products when 5 is selected from set ...” January 19, 2019 Brent@GMATPrepNow posted a reply to If Sam were twice as old as he is, he would be 40 years in the Problem Solving forum “Jim is 10 years younger than Sam Let x = Sam''s PRESENT age So, x - 10 = Jim''s PRESENT age If Sam were twice as old as he is, he would be 40 years older than Jim. TWICE Sam''s age = 2x So, we can write: 2x = (x - 10) + 40 Simplify: 2x = x + 30 Solve: x = 30 Answer: B Cheers, Brent” January 19, 2019 Brent@GMATPrepNow posted a reply to One night a certain hotel rented 3/4 of its rooms, including in the Problem Solving forum “This question is a great candidate for the Double Matrix method, whichcan be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of motel rooms, and the two characteristics are: - air conditioning or no air ...” January 19, 2019 GMATGuruNY posted a reply to In a certain pet shop, 1/3 of the pets are dogs and 1/5 of in the Data Sufficiency forum “Alternate approach: To determine the ratio of birds to dogs, plug in a TEST VALUE for the total number of pets. Let b = the number of birds and d = the number of dogs. Let the test value for the total number of pets = the LCM of 3 and 5 = 15. Since 1/5 are birds, b = 1/5 * 15 = 3. Since 1/3 ...” January 19, 2019 Brent@GMATPrepNow posted a reply to In a certain pet shop, 1/3 of the pets are dogs and 1/5 of in the Data Sufficiency forum “Target question: How many of the pets are dogs? Given: 1/3 of pets are dogs & 1/5 of pets are birds Let T = TOTAL number of pets. So, T/3 = number of dogs And T/5 = number of birds Statement 1: There are 30 birds at the pet shop So, T/5 = 30 This means that T = 150, which ...” January 19, 2019 Brent@GMATPrepNow posted a reply to Is x > y? (1) -4x + 2y < y - 3x (2) wx > wy in the Data Sufficiency forum “Target question: Is x > y? Statement 1: -4x + 2y < y - 3x Add 4x to both sides to get: 2y < y + x Subtract y from both sides to get: y < x Perfect, the answer to the target question is YES, x IS greater than y Since we can answer the target question with certainty, statement 1 ...” January 19, 2019 Brent@GMATPrepNow posted a reply to At a certain fruit stand, the price of each apple is 40 cent in the Problem Solving forum “It turns out that the cost per apple is irrelevant. Here''s why: The average (arithmetic mean) price of the 10 pieces of fruit is 56 cents So, (total value of all 10 pieces of fruit)/10 = 56 cents This means, total value of all 10 pieces of fruit = 560 cents How many oranges must Mary put ...” January 19, 2019 Brent@GMATPrepNow posted a reply to A set consists of 5 distinct positive integers a, b, c, d, e in the Problem Solving forum “The mean of all 5 numbers is 8.8 (a + b + c + d + e)/5 = 8.8 Multiply both sides by 5 to get: a + b + c + d + e = 44 The sum of a, c and e is 24 (a + c + e) = 24 So, take a + b + c + d + e = 44 and rewrite as: (a + c + e) + b + d = 44 We get: (24) + b + d = 44 So, b + d = 20 b is the ...” January 19, 2019 Brent@GMATPrepNow posted a reply to If x and y are consecutive integers such that x < y and x in the GMAT Math forum “Oops - pressed the wrong button. As you were! Brent” January 19, 2019 Brent@GMATPrepNow posted a reply to If 3 years ago Jennifer was 22 years old, how old is Carmen in the Data Sufficiency forum “Target question: How old is Carmen now? Given: 3 years ago Jennifer was 22 years old So, Jennifer''s PRESENT age is 25 Statement 1: 10 years ago, Carmen was twice as old as Jennifer. If Jennifer''s PRESENT age is 25, then Jennifer''s age 10 YEARS AGO was 15 This means Carmen''s age 10 ...” January 19, 2019 Brent@GMATPrepNow posted a reply to In a barrel full of apples, 45% of the apples weigh more in the Problem Solving forum “No takers? Let''s say there are 100 apples in the barrel. 45% of the apples weigh MORE THAN 81 grams This means 55% of the apples weigh LESS THAN OR EQUAL to 81 grams In other words, 55 apples weigh LESS THAN OR EQUAL to 81 grams 81% of the apples weigh LESS THAN 145 grams This means 19% ...” January 18, 2019 Rich.C@EMPOWERgmat.com posted a reply to Danny and Ian are munching on a jar full of candies. Had in the Problem Solving forum “Hi All, This question is essentially a "Work Formula" question, since it has 2 people working on a task together. You have to be really careful with the details though, since the two given rates are NOT for the same task.... We''re told that Danny can finish off the jar of candies in ...” January 18, 2019 Rich.C@EMPOWERgmat.com posted a reply to A bus completed first 50 miles of a 120-mile trip at an in the Problem Solving forum “Hi All, We''re told that a bus completed first 50 miles of a 120-mile trip at an average speed of 20 mph. Then it took a halt of 30 minutes and completed half of the remaining journey at an average speed of 35 mph. We''re asked for the average speed it should complete the REMAINING part of the ...” January 18, 2019 GMATGuruNY posted a reply to How many hours did it take Helen to drive from her house to in the Data Sufficiency forum “Statement 1: If d=72, then t = d/r = 72/72 = 1 hour. If d=144, then t = 144/72 = 2 hours. Since the time can be different values, INSUFFICIENT. Statement 2: Time and rate have a RECIPROCAL RELATIONSHIP: If the time is cut in HALF, then the rate DOUBLES. If the time DOUBLES, then the ...” January 18, 2019 Brent@GMATPrepNow posted a reply to Passing the 30-question third section in the Data Sufficiency forum “ Given: A dental licensure exam requires a 75% minimum score in order to pass each section Target question: Did Jennifer pass the 30-question third section? 75% of 30 = 22.5 So, in order to get at least 75% in the 3rd section, Jennifer must correctly answer 23 or more questions in the 3rd ...” January 18, 2019 Brent@GMATPrepNow posted a reply to 32 teams compete in the World Cup of Soccer. They are divid in the Problem Solving forum “Perfect approach! ASIDE: We have 4 teams, and 2 teams play a game. So, the number of games played = the number of different ways to select 2 of the 4 teams = 4C2 = 6 Cheers, Brent” January 18, 2019 Brent@GMATPrepNow posted a reply to Does (a – 2)(b + 4) = 8? in the GMAT Math forum “Target question: Does (a – 2)(b + 4) = 8? This is a good candidate for rephrasing the target question. When I SCAN the statements, I see that statement 1 has the term ab. This suggests to me that we might benefit from EXPANDING the expression, since that will result in an ab term. Take: (a ...” January 18, 2019 Brent@GMATPrepNow posted a reply to A fair die has sides labeled with 1, 2, 3, 4, 5, and 6 dots. in the GMAT Math forum “We want P(select at least one 6) When it comes to probability questions involving "at least," it''s best to try using the complement. That is, P(Event A happening) = 1 - P(Event A not happening) So, here we get: P(getting at least one 6) = 1 - P(not getting at least one 6) What does ...” January 18, 2019 Brent@GMATPrepNow posted a reply to If x and y are consecutive integers such that x < y and x in the GMAT Math forum “GIVEN: x and y are consecutive integers such that x < y So, if x is ODD, then y is EVEN One option here is to replace the x''s and y''s with ODD and EVEN and apply the rules for ODDs and EVENs. Or we can just replace x and y with odd and even numbers. Let''s do that. Replace x with 1 ...” January 18, 2019 Brent@GMATPrepNow posted a reply to is x > 0? in the GMAT Math forum “Target question: Is x > 0 ? Statement 1: x – y > –8 This statement doesn''t feel sufficient, so I''ll TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 1 and y = 0. In this case, the answer to the target question is YES, x ...” January 18, 2019 Brent@GMATPrepNow posted a reply to If x is an integer greater than 2, the function f(x) in the GMAT Math forum “The key here is that f(51) is EQUAL to f(50) Here''s why: According to the definition of the function f, f(51) = (2)(4)(6). . . (48)(50), and f(50) = (2)(4)(6). . . (48)(50) So, f(51) - f(50) = (2)(4)(6). . . (48)(50) - (2)(4)(6). . . (48)(50) = 0 Answer: E Cheers, Brent” January 18, 2019 GMATGuruNY posted a reply to If tank X contains only gasoline, how many kiloliters of gas in the Data Sufficiency forum “Let G = the gas in the tank and C = the capacity of the tank. Statement 1: G - (1/2)G = (1/3)C No way to solve for G. INSUFFICENT. Statement 2: G + 0.75 = C No way to solve for G. INSUFFICIENT. Statements combined: Since we have two variables (G and C) and two distinct linear ...” January 18, 2019 Rich.C@EMPOWERgmat.com posted a reply to Three children, John, Paul, and Ringo, are playing a game. in the Problem Solving forum “Hi All, We''re told that three children - John, Paul, and Ringo, are playing a game. Each child will choose either the number 1 or the number 2. When one child chooses a number DIFFERENT from those of the other two children, he is declared the winner. If all of the children choose the SAME ...” January 18, 2019 Rich.C@EMPOWERgmat.com posted a reply to A will was written such that an estate would be divided amon in the Problem Solving forum “Hi All, We''re told that a will was written such that an estate would be divided among FIVE beneficiaries with the remainder donated to charity, with one stipulation in the will is that no one beneficiary can receive an amount within 20% of another''s amount. One of the beneficiaries received ...” January 18, 2019 Rich.C@EMPOWERgmat.com posted a reply to If Jake loses 8 pounds, he will weigh twice as much as his s in the Problem Solving forum “Hi All, This question can be solved with fairly straight-forward Algebra (as some of the other solutions have proven). It can also be solved by TESTing THE ANSWERS and a bit of logic. We''re told that the total weight of Jake and his sister is 278 pounds. We''re also told that if Jake lost 8 ...” January 18, 2019 Rich.C@EMPOWERgmat.com posted a reply to Need Suggestion on books in the GMAT Strategy forum “Hi JOHNMC, Raising a 430 to the point that you could consistently score 700+ will likely require at least another 3 months of consistent, guided study - and you''ll have to make significant improvements to how you handle BOTH the Quant and Verbal sections. Thankfully, the GMAT is a consistent, ...” January 18, 2019 Brent@GMATPrepNow posted a reply to What percentage of his bills did Stanley pay before their in the Data Sufficiency forum “Target question: What percentage of his bills did Stanley pay before their due dates last month? This is a great candidate for rephrasing the target question. Aside: We have a free video with tips on rephrasing the target question: Let P = # of bills PAID before due date Let T = TOTAL # of ...” January 17, 2019 Brent@GMATPrepNow posted a reply to Overlapping figures in the Problem Solving forum “If the area of the square is 4, then each side has length 2 https://i.imgur.com/Ul16WsZ.png At this point, we have a special 30-60-90 right triangle. When we compare this blue triangle to the BASE 30-60-90 right triangle . . . https://i.imgur.com/vrYSacE.png . . . we see that the blue ...” January 17, 2019 GMATGuruNY posted a reply to If Jake loses 8 pounds, he will weigh twice as much as his s in the Problem Solving forum “Here, the value in red is the sum of Jake''s weight and TWICE the sister''s weight: 187 + 2(89.5) = 366. But the prompt gives an integer value for the sum of Jake''s weight and the sister''s ACTUAL weight -- a constraint that forces Jake''s weight to be an even integer.” January 17, 2019 GMATGuruNY posted a reply to If Jake loses 8 pounds, he will weigh twice as much as his s in the Problem Solving forum “The sum of Jake''s weight and his sister''s weight is an INTEGER VALUE. The answer choices indicate that Jake''s weight is an INTEGER VALUE. Implication: The sister''s weight must also be an integer value. Thus, the value in red -- 89.5 -- is not a valid option for the sister''s weight. Given ...” January 17, 2019 Brent@GMATPrepNow posted a new topic called Set A = {2, 3, 4, 5}, and set B = {4, 5, 6, 7, 8}. If P = th in the Problem Solving forum “Set A = {2, 3, 4, 5}, and set B = {4, 5, 6, 7, 8}. If P = the product of one number chosen from set A and one number chosen from set B, how many DIFFERENT values of P are possible? A) 14 B) 15 C) 16 D) 18 E) 20 Answer: C Difficulty level: 600 - 650 Source: www.gmatprepnow.com” January 17, 2019 Brent@GMATPrepNow posted a reply to If 20 Swiss Francs is enough to buy 9 notebooks in the Data Sufficiency forum “Target question: Is 40 Swiss Francs enough to buy 12 notebooks and 12 pencils? This is a great candidate for rephrasing the target question. Let N = the cost of 1 notebook (in Swiss francs) Let P = the cost of 1 pencil (in Swiss francs) So, 12 notebooks cost 12N and 12 pencils cost 12P ...” January 17, 2019 GMATGuruNY posted a reply to The speed of a boat is 5 times the speed at which a river fl in the Problem Solving forum “Let the river''s rate = 1 mph and the boat''s rate = 5 mph. When the boat travels DOWNRIVER, the boat and the river WORK TOGETHER, so we ADD their rates: 5+1 = 6 mph. When the boat travels UPRIVER, the boat and the river COMPETE, so we SUBTRACT their rates: 5-1 = 4 mph. Rate and time have ...” January 17, 2019 GMATGuruNY posted a reply to If Jake loses 8 pounds, he will weigh twice as much as his s in the Problem Solving forum “ALWAYS KEEP YOUR EYE ON THE ANSWER CHOICES. If Jake loses 8 pounds, he will weigh twice as much as his sister. j-8 = 2s j = 2s + 8 = even + even = even. Since Jake''s weight must be an EVEN VALUE, the correct answer is E.” January 17, 2019 Brent@GMATPrepNow posted a reply to The speed of a boat is 5 times the speed at which a river fl in the Problem Solving forum “Let x = the speed of the river (in miles per hour) So, 5x = the speed of the boat in (miles per hour) Let d = distance traveled (in miles) This means the boat''s speed going UPriver = 5x - x = 4x And the boat''s speed going DOWNriver = x + 5x = 6x time = distance/speed So, travel time ...” January 17, 2019 Brent@GMATPrepNow posted a reply to If Jake loses 8 pounds, he will weigh twice as much as his s in the Problem Solving forum “Here''s a solution that uses one variable. Let x = Jake''s present weight in pounds So, x - 8 = Jake''s hypothetical weight IF he were to lose 8 pounds If Jake loses 8 pounds, he will weigh twice as much as his sister. In other words, the sister weighs HALF as much as Jake''s hypothetical ...” January 17, 2019 Brent@GMATPrepNow posted a reply to Three children, John, Paul, and Ringo, are playing a game. in the Problem Solving forum “The main concept here is that all 3 children are equally likely to win this game (unless one of them possesses supernatural powers that allow him to know what numbers the other two boys will choose :-)) Also note that, if everything is random, the probability of winning by choosing the number 2 ...” January 16, 2019 Brent@GMATPrepNow posted a new topic called In a barrel full of apples, 45% of the apples weigh more in the Problem Solving forum “In a barrel full of apples, 45% of the apples weigh more than 81 grams, and 81% of the apples weigh less than 145 grams. What percent of the apples in the barrel weigh more than 81 grams but less than 145 grams? A) 16 B) 18 C) 26 D) 32 E) 36 Answer: C Difficulty level: 600 - 650 Source: ...” January 16, 2019 Brent@GMATPrepNow posted a reply to What is the surface area of the solid right circular in the Problem Solving forum “Given: radius = 3 Height = 10 Surface area of cylinder = 2πr² + 2πrh = 2π(3²) + 2π(3)(10) = 18π + 60π = 78π Answer: D Cheers, Brent” January 16, 2019 Brent@GMATPrepNow posted a reply to Three children, John, Paul, and Ringo, are playing a game. in the Problem Solving forum “This is one of my all-time favorite questions!! The main concept here is that all 3 children are equally likely to win this game (unless one of them possesses supernatural powers that allow him to know what numbers the other two boys will choose :-)) Also note that, if everything is random, ...” January 16, 2019 Rich.C@EMPOWERgmat.com posted a reply to Mixture A is 15 percent alcohol, and mixture B is 50 percent in the Problem Solving forum “Hi All, We''re told that Mixture A is 15 percent alcohol and mixture B is 50 percent alcohol and when a certain amount of each is poured together to create a 4-gallon mixture, the result contains 30 percent alcohol. We''re asked approximately how many gallons of mixture A are in the mixture. ...” January 16, 2019 Rich.C@EMPOWERgmat.com posted a reply to Which of the following equations represents a line in the Problem Solving forum “Hi All, We''re asked which of the 5 answers is the equation for a line that is perpendicular to line K in the figure above. This question is based on line/graphing rules. To start, a PERPENDICULAR line is one that has an "opposite inverse" slope (sometime called a "negative ...” January 16, 2019 Rich.C@EMPOWERgmat.com posted a reply to If a certain concrete mixture contains gravel, water, and in the Problem Solving forum “Hi All, We''re told that a certain concrete mixture contains gravel, water, and sand in a ratio of 1 to 3 to 5 by weight. We''re asked for the number of pounds of gravel that would be needed to produce 72 pounds of the mixture. This math behind this question can be approached in a number of ...” January 16, 2019 Rich.C@EMPOWERgmat.com posted a reply to Need Suggestion on books in the GMAT Strategy forum “Hi JOHNMC, Since it sounds like you''re just beginning your studies, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can take 2 for free at www.mba.com (and they come with some additional practice materials). If you want to do a little studying first, so that you can ...” January 16, 2019 GMATGuruNY posted a reply to Sarah is in a room with 6 other children. If the other child in the Data Sufficiency forum “Let S = Sara''s age. Sum of the ages = 2+4+5+8+10+13+S = 42+S. Statement 1: Since the average age is equal to an INTEGER -- the fourth largest age -- we get: Sum of the ages = (number of ages)(average age) = (7)(INTEGER) = multiple of 7. The blue expression and the red expression each ...” January 16, 2019 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 From 2000 to 2003, the number in the Problem Solving forum “From 2000 to 2003, the number of employees at a certain company increased by a factor of 1/4 Let x = the number of employees in 2000 So, the number of employees in 2003 = x + (1/4)x = (5/4)x From 2003 to 2006, the number of employees at this company decreased by a factor of 1/3 (5/4)x = the ...” January 16, 2019 Brent@GMATPrepNow posted a reply to The usual price of a bagel was reduced during a sale. How mu in the Data Sufficiency forum “Target question: How much money could be saved by purchasing 10 bagels at the sale price rather than at the usual price? Statement 1: The usual price for a bagel is$0.50 per bagel. Since there''s no information about the SALE price, there''s no way to calculate the amount saved. Since we ...”
January 16, 2019
GMATGuruNY posted a reply to If the median and the range of the data set 1, 1, 2, 2, 3, 3 in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the value of m. When the correct answer is plugged in, the median will be equal to the range. Note: When the prompt includes the phrase which of the following, the correct answer is likely to be D or E. E: m=3 Resulting set: 1, 1, 2, 2, m=3, 3, 3, ...”
January 16, 2019
Rich.C@EMPOWERgmat.com posted a reply to In a 200 member association consisting of men and women, exa in the Problem Solving forum
“Hi All, We''re told that in a 200 member association consisting of men and women, exactly 20% of men and exactly 25 % women are homeowners. We''re asked for the LEAST number of members who are homeowners. This question is built around a couple of Number Properties - and to MINIMIZE the number of ...”
January 15, 2019
Rich.C@EMPOWERgmat.com posted a reply to Roger wants to arrange three of his five books on his in the Problem Solving forum
“Hi All, We''re told that Roger wants to arrange three of his five books on his bookshelf, but two of the five books are duplicates and cannot both be selected. We''re asked for the number different ways that Roger can arrange his books. The wording of this question is a bit ''quirky'', but the ...”
January 15, 2019
GMATGuruNY posted a reply to Henry eats X scones in X percent of the time it takes Rachel in the Problem Solving forum
“Let X=8 and Y=4. Henry eats X scones in X percent of the time it takes Rachel to eat Y scones. Since Henry eats X=8 scones in 8% of the time it takes Rachel to eat Y=4 scones -- 10 minutes, according to the prompt -- the time for Henry to eat 8 scones = 8% of 10 minutes = (8/100)(10) = 4/5 ...”
January 15, 2019
Brent@GMATPrepNow posted a reply to Henry eats X scones in X percent of the time it takes Rachel in the Problem Solving forum
“Let''s use the INPUT-OUTPUT approach. Let''s assign some values of X and Y so that they satisfy the information in the question. Let X = 25. This means Henry eats 25 scones in 25 percent of the time it takes Rachel to eat Y scones Let Y = 100. This means Henry eats 25 scones in 25 percent of ...”
January 15, 2019
Brent@GMATPrepNow posted a reply to Roger wants to arrange three of his five books on his in the Problem Solving forum
“I''m not crazy about this question. The official answer suggests that, although 2 books are DUPLICATES, they''re still considered DIFFERENT. Here''s what I mean: Let''s let D and d represent the two duplicate books. Let, A, B and C represent the other three books. The official answer ...”
January 15, 2019
Brent@GMATPrepNow posted a reply to The three-digit positive integer n can be written as ABC, in in the Data Sufficiency forum
“IMPORTANT point: The VALUE of a 3-digit integer xyz is 100x + 10y + z Example: 723 = (7)(100) + (2)(10) + 3 Target question: What is the remainder when n is divided by 37? Statement 1: A + B/10 + C/100 = B + C/10 + A/100 Multiply both sides by 100 to get: 100A + 10B + C = 100B + 10C + ...”
January 15, 2019
Brent@GMATPrepNow posted a reply to If x, y are integers, is x^2+x+y an odd integer? in the Data Sufficiency forum
“ Given: x and y are integers Target question: Is x² + x + y an odd integer? This is a good candidate for rephrasing the target question. Take x² + x + y and factor the first two terms to get: x(x + 1) + y Notice that x and x+1 are CONSECUTIVE INTEGERS, which means one value is ODD and ...”
January 15, 2019
GMATGuruNY posted a reply to A rectangular wall has dimensions of 800 by 300. If the wall in the Problem Solving forum
“number of tiles = (wall area)/(tile area) = (800*300)/(25*12) = 32*25 = 800. The correct answer is E.”
January 15, 2019
GMATGuruNY posted a reply to In a 200 member association consisting of men and women, exa in the Problem Solving forum
“Consider the following equation: 7x + 5y = 70. If x and y are nonnegative integers, the following solutions are possible: x=10, y=0 x=5, y=7 x=0, y=14. Notice the following: The value of x changes in increments of 5 (the coefficient for y). The value of y changes in increments of ...”
January 15, 2019