# 800guy

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Brent@GMATPrepNow posted a reply to The product of 4 consecutive odd integers is negative. What in the Data Sufficiency forum
“Target question: What is the largest odd integer? Given: The product of 4 consecutive odd integers is negative. It''s worth taking the time to analyze what this is telling us. If the product of 4 consecutive odd integers is negative, then there are only 2 possible scenarios: Scenario #1: ...”
July 17, 2018
Brent@GMATPrepNow posted a reply to Is x<0? in the GMAT Math forum
“Target question: Is x<0? Key Concept: ODD exponents preserve the sign of the base. In other words, POSITIVE^ODD = POSITIVE and NEGATIVE^ODD = NEGATIVE Statement 1: x^5 < 0 This is telling us that x^5 = NEGATIVE So, it must be the case that x is NEGATIVE So, the answer to the ...”
July 17, 2018
Brent@GMATPrepNow posted a reply to In the xy-plane, points A, B and C are not on the same line in the Data Sufficiency forum
“Target question: Is the slope of line BC negative? We can quickly see that statements 1 and 2 (alone) are NOT SUFFICIENT. This brings us to... Statements 1 and 2 combined If we draw the line segment AB with slope -1, then we get something like this: ...”
July 17, 2018
Brent@GMATPrepNow posted a reply to If x < 12, then it must be true that in the Problem Solving forum
“NOTE: this is one of those questions that require us to check/test each answer choice. In these situations, always check the answer choices from E to A, because the correct answer is typically closer to the bottom than to the top. For more on this strategy, see my article: ...”
July 17, 2018
Brent@GMATPrepNow posted a reply to If 8x=2^y what is the value of x, in terms of y? in the Problem Solving forum
“Another approach is to find some values of x and y that satisfy the given equation 8x = 2^y One solution that works is x = 1 and y = 3, since 8(1) = 2^3 Now take each answer choice and replace x and y with 1 and 3 respectively and see which one yields a true equation: A. 1 = 2^[3(3) - 2] ...”
July 17, 2018
Brent@GMATPrepNow posted a reply to Challenge: If line k passes through the points (48, 33) and in the Problem Solving forum
“If we sketch the two given points, we can quickly see that the slope (aka rise/run) of the line = 11/17 https://i.imgur.com/jJtP4PZ.png So, we can use this information to plot another point on the line... https://i.imgur.com/pfA3jL1.png And another point... ...”
July 11, 2018
Brent@GMATPrepNow posted a reply to Challenge question: If ABCD is a square, and XYZ in the Problem Solving forum
“If ∆XYZ is EQUILATERAL, then each angle is 60° So, if we draw a line from the center to a vertex, we''ll get two 30° angles.... https://i.imgur.com/4s2wG5R.png Now drop a line down like this to create a SPECIAL 30-60-90 right triangle https://i.imgur.com/aLVDzG4.png Since the base ...”
July 10, 2018
Brent@GMATPrepNow posted a new topic called Challenge: If line k passes through the points (48, 33) and in the Problem Solving forum
“If line k passes through the points (48, 33) and (31, 22), what is the x-intercept of line k? A) -25 10/11 B) -3 C) -1 16/17 D) 1 16/17 E) 25 10/11 Answer: B Difficulty level: 600 – 650 Source: www.gmatprepnow.com *I''ll post a solution in 2 days”
July 9, 2018
Brent@GMATPrepNow posted a reply to What is the area of the shaded region, if the area of the in the Problem Solving forum
“EXTRA PRACTICE Here are two more questions involving an equilateral triangle inscribed in a circle: - http://www.beatthegmat.com/triangle-inside-a-circle-t90961.html - http://www.beatthegmat.com/if-a-smaller-circle-is-inscribed-in-an-equilateral-triangle-t289365.html Cheers, Brent”
July 9, 2018
Brent@GMATPrepNow posted a reply to Jalal weighs twicw as much as Meena. Meena's weight is 60% in the Problem Solving forum
“An alternative approach is to assign weights that meet the given conditions. Meena''s weight is 60% of Bahar''s weight Let''s let Bahar''s weight = 100 kg So, Meena''s weight = 60 kg Jalal weighs twice as much as Meena. Since Meena weight 60 kg (see above) then Jalal''s weight = 120 kg ...”
July 8, 2018
Brent@GMATPrepNow posted a new topic called Challenge question: If ABCD is a square, and XYZ in the Problem Solving forum
“https://i.imgur.com/sd4EcIB.png If ABCD is a square, and XYZ is an equilateral triangle, then the area of the square is how many times the area of the triangle? A) (4√3)/3 B) (8√3)/3 C) 2√6 D) (16√3)/9 E) (16√2)/3 Answer: D Difficulty level: 650 – 700 Source: ...”
July 8, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 If S = 1 + in the Problem Solving forum
“So, S = 1 + 1/4 + 1/9 + 1/16 + 1/25 + 1/36 + . . . . Now, let''s convert a few of the fractions to decimal approximations... S = 1 + 0.25 + 0.11 + 0.06 + 0.04 + . . . Add the first 4 values.... S = 1.42 + 0.04 + . . . IMPORTANT: Notice that each fraction is less than the fraction ...”
July 8, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 In the xy-coordinate plane 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 ...”
July 7, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Greg assembles units of a certain in the Problem Solving forum
“GIVEN: Total pay for 2 days is $180 In order to MAXIMIZE the number of units assembled on one of the days, we must MINIMIZE the number of units assembled on the other day We''re told that Greg assembled at least 30 units each day. So, the MINIMUM is 30 units Let''s say that Greg assembled 30 ...” July 7, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Which of the following is closest in the Problem Solving forum “ALWAYS check the answer choices before solving the question! When we do so, we see that the answer choices are VERY spread apart, which means we can save a ton of time by being super aggressive with our approximations (aka rounding) So, we get: √[(4.2)(1590)/15.7 ≈ √[(4)(1600)/16] ≈ ...” July 6, 2018 Brent@GMATPrepNow posted a reply to Challenge question: In the above figure, the small circle... in the Problem Solving forum “If we recognize that the hypotenuse of the blue right triangle below is twice the length of one side, we can see that this is a 30-60-90 SPECIAL TRIANGLE https://i.imgur.com/qxIw8NQ.png In the base triangle (on the right), the side opposite the 30° has length 1. So, the magnification factor of ...” July 5, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 In the figure shown in the Problem Solving forum “Since angles on a line must add to 180°, we can see that there are three 30° angles in our diagram... https://i.imgur.com/V6wFovz.png Next, let''s focus on the BLUE triangle. https://i.imgur.com/cdsQPY8.png Since angles in a triangle must add to 180° (and since we already have two angles ...” July 4, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 10, 4, 26, 16 in the Problem Solving forum “Arrange the 4 values in ascending order: {4, 10, 16, 26} Since we have an EVEN number of values, the median will be the average of the 2 middlemost values. So, the median = (10 + 16)2 = 26/2 = 13 Answer: B Cheers, Brent” July 4, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Over the past 7 weeks in the Problem Solving forum “Average = ($74 + $69 +$64 + $79 +$64 + $84 +$77)/7 = $511/7 =$73 Answer: C Cheers, Brent”
July 4, 2018
Brent@GMATPrepNow posted a reply to When the positive integer x is divided by 11 in the Problem Solving forum
“A fast approach is to find a value of x that meets the given conditions. When the positive integer x is divided by 11, the quotient is y and the remainder 3. When x is divided by 19, the remainder is also 3.... Notice that x = 3 meets the above conditions. 3 divided by 11 = 0 with remainder ...”
July 4, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 The value of the above in the Problem Solving forum
“One option is to replace each fraction in the NUMERATOR with its decimal approximation. 7/8 ≈ 0.88 1/9 ≈ 0.11 1/2 = 0.5 So, (7/8 + 1/9)/(1/2) ≈ (0.88 + 0.11)/(1/2) ≈ (0.99)/(1/2) ≈ 1/(1/2) ≈ 2 Answer: A Cheers, Brent”
July 4, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 If a + b + c = 12 in the Data Sufficiency forum
“Target question: What is the value of b ? Given: a + b + c = 12 Statement 1: a + b = 8 We can take a + b + c = 12 and rewrite it as (a + b) + c = 12 Now replace a+b with 8 to get: (8) + c = 12 Solve: c = 4 Now that we know the value of c, can we find the value of b? No. Let''s ...”
July 4, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 The table shows partial results in the Problem Solving forum
“Since we aren''t told the number of people involved in the survey, let''s make things easier on ourselves and assign a "nice" value to the number of people involved in the survey. Let''s say there were 100 people in the survey. When we apply this to our table, we see that 35 people ...”
July 4, 2018
Brent@GMATPrepNow posted a reply to Challenge question: If j and k are positive integers, and (k in the Problem Solving forum
“Let''s focus on the value of j. Since j is an integer, it must be the case that j^6 equals some power of 6. So, for example, j^6 could equal 29^6. Likewise, j^6 could equal 29^12, because we can rewrite 29^12 as (29^2)^6 in which case, we can see that (29^2)^6 is a power of 6 Likewise, j^6 ...”
July 3, 2018
Brent@GMATPrepNow posted a new topic called Challenge question: In the above figure, the small circle... in the Problem Solving forum
“https://i.imgur.com/XrqxGNd.png In the above figure, the small circle and big circle have diameters of 3 and 6 respectively. If AB||CD, and both circles share the same center, what is the area of the shaded region? A) 9/2 + 2π B) 9/2 + 3π C) 3√3 + 3π D) 6√3 + 2π E) (9/2)√3 + ...”
July 3, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Ron is 4 inches taller than in the Problem Solving forum
“Let A = Amy''s height So, A + 4 = Ron''s height And A + 5 = Barbara''s height If Barbara''s height = 65, then we can write: A + 5 = 65 Solve to get: A = 60 So, Amy''s height is 60, Ron''s height is 64 and Barbara''s height is 65 So, the median height = 64 Answer: E Cheers, Brent”
July 3, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 While a family was away on in the Problem Solving forum
“..... paid a neighborhood boy $11 per week to mow their lawn... So, in 3 weeks, the amount the family paid for lawn-moving = (3 weeks)($11/week) = $33 ...the family paid$4 per DAY to feed and walk their dog... 3 weeks = 21 DAYS So, the amount the family paid for dog care = (21 days)($4/day) = ...” July 3, 2018 beatthegmat posted a new topic called The Smart Choice: Benefits of Taking the GRE® General Test in the GMAT Strategy forum “Are you thinking of pursuing a professional business degree? More business school students than ever before are getting into top-ranked business programs using GRE<sup>®</sup> scores. You do have testing options. If you’re weighing which test is right for you, this overview of the ...” July 2, 2018 Brent@GMATPrepNow posted a reply to What is the ratio of 2a to b? in the Data Sufficiency forum “Target question: What is the ratio of 2a to b? In other words, What is the value of 2a/b? Statement 1: a/b = 2 Take: a/b = 2 Multiply both sides by 2 to get: 2a/b = 4 So, the answer to the target question is 2a/b = 4 Since we can answer the target question with certainty, statement 1 is ...” July 2, 2018 Brent@GMATPrepNow posted a reply to A certain company employs 6 senior officers and 4 junior in the Problem Solving forum “Take the task of creating the 4-person committee and break it into stages. Stage 1: Select 3 senior officers Since the order of the selected officers does not matter, we can use combinations. We can select 3 officers from 6 senior officers 6C3 ways (= 20 ways) Stage 2: Select 1 junior ...” July 2, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 If the circumference of a in the Problem Solving forum “We have the following: https://i.imgur.com/NccAGgy.png The perimeter of the circle = 25π We can see that the perimeter of the square is GREATER THAN the perimeter of the circle 25π ≈ (25)(3) ≈ 75 So, the perimeter of the square is GREATER THAN 25π Check the answer ...” July 2, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 If the circumference of a in the Problem Solving forum “We have the following: https://i.imgur.com/NccAGgy.png The perimeter of the circle = 25π We can see that the perimeter of the square is GREATER THAN the perimeter of the circle 25π ≈ (25)(3) ≈ 75 So, the perimeter of the square is GREATER THAN 25π Check the answer ...” July 2, 2018 Brent@GMATPrepNow posted a new topic called Challenge question: If j and k are positive integers, and (k in the Problem Solving forum “If j and k are positive integers, and (k)(j^6) = (29^29)(11^11), then how many possible values of k are there? A) 8 B) 10 C) 12 D) 15 E) 18 Answer: B Difficulty level: 650-700 Source: www.gmatprepnow.com *I''ll post a solution in 2 days” July 1, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 In a recent town election in the Data Sufficiency forum “Let F = the number of votes in FAVOR of the proposal Let A = the number of votes AGAINST the proposal Target question: What is the value of F/A? Statement 1: There were 60 more votes in favor of the proposal than against the proposal. In other words, F = A + 60 Let''s TEST some values. ...” July 1, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Last year$48,000 of a in the Problem Solving forum
“Although I believe it''s best to use one variable to solve this question, we can also use Let x = the amount (in dollars) that ONE employee received Let y = the amount (in dollars) that ONE owner received Each owner received 3 times as much as each employee So, we can write: y = 3x Last year ...”
July 1, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Last year $48,000 of a in the Problem Solving forum “Each owner received 3 times as much as each employee Let E = the amount (in dollars) that ONE employee received So, 3E = the amount (in dollars) that ONE owner received Last year$48,000 of a certain store''s profit was shared by its 2 owners and their 10 employees. In other words: 3E + 3E + ...”
July 1, 2018
Brent@GMATPrepNow posted a reply to How old will Fred be in 3 years? in the Data Sufficiency forum
“Let''s solve the question using 2 variables Let F = Fred''s PRESENT age Let G = Gary''s PRESENT age Target question: What is the value of F+3 ? Statement 1: Presently, Fred is 4 times as old as Gary. In other words, F = 4G There are several values of F and G that satisfy the equation F ...”
June 30, 2018
Brent@GMATPrepNow posted a reply to If y is 4 greater than one-fourth of x, and in the Problem Solving forum
“The solutions above demonstrate an algebraic approach. We can also solve the question using the INPUT-OUTPUT approach. Let''s find values for x and y that satisfy the given information (y is 4 greater than one-fourth of x) A nice pair of values is x = 4 and y = 5 When we use these values, ...”
June 30, 2018
Brent@GMATPrepNow posted a reply to Tips for correcting careless mistakes in GMAT quant section in the GMAT Math forum
“If silly mistakes are hurting your score, then it''s important that you identify and categorize these mistakes. Some examples might include: - sloppy writing causes a 7 to mysteriously turn into a 1 - you forget that a question is an EXCEPT question. - you fail to notice crucial information such ...”
June 30, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Of the following, which is in the Problem Solving forum
“1.03 is a little bit BIGGER than 1 4.86 is a little bit SMALLER than 5 So, (1.03)(4.86) will be CLOSE TO (1)(5), aka 5 So, 60.2/(1.03 x 4.86) ≈ 60/(1.03 x 4.86) ≈ 60/5 ≈ 12 Answer: B Cheers, Brent”
June 30, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Robin invested a total of $12,000 in the Data Sufficiency forum “Let X = The number of dollars invested in investment X Let Y = The number of dollars invested in investment Y Target question: What is the value of Y? Given: Robin invested a total of$12,000 in two investments, X and Y, so that the investments earned the same amount of simple annual ...”
June 30, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Is the sum of the prices of the in the Data Sufficiency forum
“Target question: Is the sum of the prices of the 3 books less than $48 ? Let A = price of the LEAST expensive book (in dollars) Let B = price of the mid-priced expensive book (in dollars) Let C = price of the MOST expensive book (in dollars) So, A < B < C Statement 1: The price of ...” June 30, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 The figure above represents a in the Problem Solving forum “Let''s add the radius of 6 feet to the diagram to get: https://i.imgur.com/JSxL60Q.png From here, we can see the right triangle hiding within the diagram, which means we can apply the Pythagorean Theorem. Se can write: h² + 2² = 6² Simplify: h² + 4 = 36 So, we get: h² = 32 This means ...” June 30, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 Is in the Data Sufficiency forum “Target question: Is (x+1)/(y+1) > x/y ? Statement 1: 0 < x < y This tells us that y is POSITIVE, which means y+1 is also POSITIVE. This means we can safely take the inequality (x+1)/(y+1) > x/y and safely multiply both sides by y When we do so, we get: (y)(x+1)/(y+1) > x ...” June 30, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 During a trip that they in the Problem Solving forum “Let x = the number of miles Rafael drove Average = 80 So, (72 + 78 + 83 + x)/4 = 80 Multiply both sides by 4 to get: 72 + 78 + 83 + x = 320 Simplify: 233 + x = 320 Solve: x = 87 Answer: D Cheers, Brent” June 29, 2018 Brent@GMATPrepNow posted a reply to Algebra : Applied Problem in the Problem Solving forum “Here''s a slightly different approach. It takes 8 hours to fill to 3/5 of its capacity. So, in 1/3 the time, we''ll fill 1/3 as much. In other words, in 8/3 hours we can fill 1/5 of the pool. We want to know how long it will take to fill 2/5 of the pool. So, it will take twice as long as ...” June 29, 2018 Brent@GMATPrepNow posted a reply to Algebra : Applied Problem in the Problem Solving forum “We know it takes 8 hours to fill to 3/5 of its capacity. We want to know how long it will take to fill the remaining 2/5 of capacity. IMPORTANT: 2/5 is 2/3 as big as 3/5 So, if it takes 8 hours to fill 3/5 of the pool, then the time to fill 2/5 of the pool = (2/3)(8) hours = 16/3 hours = 5 1/3 ...” June 29, 2018 Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 A company bought 3 printers in the Data Sufficiency forum “Let P = price of ONE printer Let S = price of ONE scanner Target question: What is the value of S? Statement 1: The total price of the (3) printers and the (1) scanner was$1,300. So, we can write: 3P + S = 1300 Does this provide enough information to determine the value of S? No. ...”
June 29, 2018
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 What is the circumference in the Data Sufficiency forum
“Target question: What is the circumference of circle C ? Statement 1: The radius of circle C is 2π. Useful formula: circumference = (2π)(radius) Now that we know the radius is 2π, the circumference = 2π(2π) = 4π² In other words, the answer to the target question is the circumference ...”
June 29, 2018
Brent@GMATPrepNow posted a reply to Allison and Barbara are part of an 8-member dance troupe. in the Problem Solving forum
“Asking,"What fraction of all the possible ensembles that include Allison will also include Barbara?" is the same as asking, "What is the probability that Allison are Barbara are in the same troupe? Step 1: Place Allison in one of the troupes. Step 2: Choose the 3 remaining ...”
June 27, 2018
Brent@GMATPrepNow posted a reply to If a certain vase contains in the Data Sufficiency forum
“Here''s a solution that uses 2 variables Let R = number of roses in the vase Let T = number of tulips in the vase Target question: What is the value of T? Statement 1: The number of roses in the vase is 4 times the number of tulips in the vase. We can write: R = 4T As we can see, ...”
June 27, 2018
Brent@GMATPrepNow posted a reply to Which of the following statements in the Problem Solving forum
“There''s a nice rule that says, "In a set where the numbers are equally spaced, the mean will equal the median." For example, in each of the following sets, the mean and median are equal: {7, 9, 11, 13, 15} {-1, 4, 9, 14} {3, 4, 5, 6} Since consecutive integers are equally spaced, ...”
June 27, 2018
Brent@GMATPrepNow posted a reply to In a certain fraction, the in the Problem Solving forum
“Let N = the numerator Let D = the denominator ...the denominator is 16 greater than the numerator. We can write: D = N + 16 If the fraction is equivalent to 80 percent... We can write: N/D = 80/100 Simplify to get: N/D = 4/5 Cross multiply to get: 5N = 4D ...what is the denominator of ...”
June 27, 2018
beatthegmat started following chia021
June 27, 2018
Brent@GMATPrepNow posted a reply to If x is negative and y is positive, which of the following in the Problem Solving forum
“The key word here is MUST. So, we''re looking for an expression that must always be positive C. 2y + x If y = 10 and x = -1, then 2y + x = 2(10) + (-1) = 19. So, 2y + x CAN be positive. However, if y = 3 and x = -7, then 2y + x = 2(3) + (-7) = -1. So, 2y + x CAN be negative. Since we''re ...”
June 26, 2018
Brent@GMATPrepNow posted a reply to If x is negative and y is positive, which of the following in the Problem Solving forum
“NOTE: this is one of those questions that require us to check/test each answer choice. In these situations, always check the answer choices from E to A, because the correct answer is typically closer to the bottom than to the top. For more on this strategy, see my article: ...”
June 26, 2018
Brent@GMATPrepNow posted a reply to In a sequence of 40 numbers, each term, except for the first in the Problem Solving forum
“Notice that each term is 7 less than the term before it. This means the greatest term will be the first term In other words, term1 = 281 Let''s list a few terms of the sequence and look for a pattern: term1 = 281 term2 = 281 - 7 term3 = 281 - 7 - 7 = 218 - (2)(7) term4 = 281 - 7 - 7 - ...”
June 26, 2018
Brent@GMATPrepNow posted a new topic called How old will Fred be in 3 years? in the Data Sufficiency forum
“How old will Fred be in 3 years? (1) Presently, Fred is 4 times as old as Gary. (2) In 10 years, Fred will be 3 times as old as Gary. Answer: C Difficulty level: 550 - 600 Source: www.gmatprepnow.com”
June 26, 2018
Brent@GMATPrepNow posted a reply to Challenge question: In a group of x students, w students are in the Problem Solving forum
“Let''s apply the Double Matrix Method, a technique that 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 students, and the two characteristics are: - taking French ...”
June 26, 2018
Brent@GMATPrepNow posted a new topic called If y is 4 greater than one-fourth of x, and in the Problem Solving forum
“If y is 4 greater than one-fourth of x, and x ≠ 0, what is the ratio of y to x in terms of x? A) (x² + 16x)/4 B) (4x + 16)/x C) (x + 16)/4x D) (4x + 1)/x E) (x + 16)/x Answer: C Difficulty level: 550-600 Source: www.gmatprepnow.com *I''ll post a solution in 2 days”
June 25, 2018
Brent@GMATPrepNow posted a reply to OG Mixtures Problem in the Problem Solving forum
“This looks like a job for weighted averages! Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ... Mixture X is 40 percent ryegrass Mixture Y is 25 percent ryegrass Let x = the ...”
June 25, 2018
Brent@GMATPrepNow posted a reply to gmat prep question in the Problem Solving forum
“Here''s the complete question (with answer choices): Height of tree on day 0 = 4 Let d = the height increase each year Height of tree at the end of the 1st year = 4+d Height of tree at the end of the 2nd year = 4+d+d = 4 + 2d Height of tree at the end of the 3rd year = 4+d+d+d = 4 + 3d ...”
June 25, 2018
Brent@GMATPrepNow posted a reply to Alice and Bob drive the same car. Alice drives the car for 1 in the Problem Solving forum
“Let T = total distance traveled Alice drives the car for 1/4 of one trip, and Bob drives the car for the remainder of the same trip In other words, Bob drove 3/4 the distance. We can write: (1/4)T = distance Alice drove And (3/4)T = distance Bob drove The difference between the distance ...”
June 25, 2018
Brent@GMATPrepNow posted a reply to Within a group of students, x students are taking English, y in the Problem Solving forum
“We can solve this by using 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 students, and the two characteristics are: - ...”
June 24, 2018
Brent@GMATPrepNow posted a new topic called Challenge question: In a group of x students, w students are in the Problem Solving forum
“In a group of x students, w students are taking Chemistry but not French, y students are taking French but not Chemistry, and z students are NOT taking French. Which of the following represents the number of students who are taking Chemistry? A) x - y - z - w B) x - y + z + w C) x - y - z + w ...”
June 24, 2018
Brent@GMATPrepNow posted a reply to Challenge: How many positive integers less than 500 begin in the Problem Solving forum
“Here''s a different approach: There are 499 integers from 1 to 499 inclusive. Let''s determine how many of those 499 integers DO NOT meet the condition of beginning with a 3, ending with a 3, or both 1-digit integers that DO NOT begin with a 3, end with a 3, or both 1, 2, 4, 5, 6, 7, 8, ...”
June 22, 2018
Brent@GMATPrepNow posted a new topic called Within a group of students, x students are taking English, y in the Problem Solving forum
“Within a group of students, x students are taking English, y students are taking Math, and z students are taking both English and Math. Which of the following represents the number of students who are taking English or Math but not both? A) x + y - z B) x + y + z C) 2x + 2y - z D) x + y - 2z ...”
June 21, 2018
Brent@GMATPrepNow posted a reply to When a, b and c are consecutive positive even integers such in the Problem Solving forum
“If a, b and c are consecutive EVEN integers, and a>b>c, then we we know that b is 2 greater than c, and a is 2 greater than b So, we can write: b = c + 2 a = c + 4 Now let''s check the answer choices from E to A -----ASIDE---------------- This is one of those questions that require ...”
June 21, 2018
Brent@GMATPrepNow posted a reply to GMATPrep Exponent Problem in the Problem Solving forum
“4^17 - 2^28 = (2²)^17 - 2^28 = 2^34 - 2^28 = 2^28(2^6 - 1) = 2^26(64- 1) = (2^26)(63) = (2^26)(3)(3)(7) So, the PRIME factors are 2, 3, and 7 Answer: D Cheers, Brent”
June 21, 2018
Brent@GMATPrepNow posted a reply to Problem involving prime factors in the Problem Solving forum
“Important Concept: If integer k is greater than 1, and k is a factor (divisor) of N, then k is not a divisor of N+1 For example, since 7 is a factor of 350, we know that 7 is not a factor of (350+1) Similarly, since 8 is a factor of 312, we know that 8 is not a factor of 313 Now let’s ...”
June 21, 2018
Brent@GMATPrepNow posted a reply to Challenge question: N is a 2-digit integer. When the di in the Data Sufficiency forum
“Target question: What is the value of N? Given: N is a 2-digit integer. When the digits of N are reversed, the resulting number is M. -1 < N – M < 15 Let x = the tens digit of N Let y = the units digit of N So, the VALUE of N = 10x + y When we reverse the digits, we get M = yx ...”
June 20, 2018
Brent@GMATPrepNow posted a reply to If s is a positive integer, is s prime? in the Data Sufficiency forum
“Target question: Is s prime? Given: s is a positive integer Statement 1: 21/s is an integer So, s can equal 1, 3, 7 or 21 If s = 1, the answer to the target question is NO, s is NOT prime If s = 3, the answer to the target question is YES, s IS prime Since we cannot answer the target ...”
June 20, 2018
Brent@GMATPrepNow posted a reply to What is the maximum number of points of intersection of in the Problem Solving forum
“With a quick sketch.... https://i.imgur.com/1knFxvl.png ....we can get 2 points of intersection. With the exception of a formal proof, we''re left on our own accord to find a situation with more than 2 points of intersection. If we can''t identify such a situation, we must go with C ...”
June 20, 2018
Brent@GMATPrepNow posted a reply to Challenge question: Each edge of the above cube has length 1 in the Problem Solving forum
“If we open up the cube, we get something like this.... https://i.imgur.com/9LRJhWQ.png Let x = the distance from A to B https://i.imgur.com/xuj615V.png Since we have a right triangle, we can apply the Pythagorean Theorem to get: 1² + 2² = x² Simplify to get: 1 + 4 = x² So, 5 = x², which ...”
June 20, 2018
Brent@GMATPrepNow posted a reply to A house cost Ms. Jones C dollars in 1965. Three years in the Problem Solving forum
“A house cost Ms. Jones C dollars in 1965. Three years later she sold the house for 25% more than she paid for it. So, 3 years later, the house sold for 1.25C dollars She has to pay a tax of 50% of the gain. (The gain is the selling price minus the cost.) How much tax must Ms. Jones pay? Gain = ...”
June 20, 2018
Brent@GMATPrepNow posted a new topic called Challenge: How many positive integers less than 500 begin in the Problem Solving forum
“How many positive integers less than 500 begin with a 3, end with a 3, or both? A) 149 B) 150 C) 159 D) 199 E) 200 Answer: A Difficulty level: 600 – 650 Source: www.gmatprepnow.com *I''ll post a full solution in 2 days”
June 20, 2018
Brent@GMATPrepNow posted a reply to Challenge: Is AB || CD? in the Data Sufficiency forum
“Target question: Is AB || CD? I''ll use the two shapes below (rectangle and isosceles trapezoid) show that the correct answer is E https://i.imgur.com/zRR75tm.png Statement 1: AC = BD Notice that rectangle and isosceles trapezoid both satisfy the condition that AC = BD ...”
June 20, 2018
Brent@GMATPrepNow posted a new topic called Challenge question: N is a 2-digit integer. When the di in the Data Sufficiency forum
“N is a 2-digit integer. When the digits of N are reversed, the resulting number is M. If -1 < N – M < 15, what is the value of N? (1) The sum of N’s digits is 15. (2) The tens digit of N is 1 greater its units digit Answer: A Difficulty level: 650 - 700 Source: ...”
June 19, 2018
Brent@GMATPrepNow posted a reply to Rate my AWA in the GMAT Essays (AWA) forum
“My 2 cents: I like the idea of starting with a summary of the original argument, but your argument summary is only 2 words shorter than the original argument. Your last paragraph deviates from the primary goal of the essay (determine how well the conclusion follows from the premise). Instead, ...”
June 18, 2018
Brent@GMATPrepNow posted a new topic called Challenge: Is AB || CD? in the Data Sufficiency forum
“https://i.imgur.com/qNiBsQb.png Is AB || CD? (1) AC = BD (2) AB = CD Answer: E Difficulty level: 600 - 650 Source: www.gmatprepnow.com *I''ll post a full solution in 2 days”
June 18, 2018
Brent@GMATPrepNow posted a reply to What is the volume of the largest cube that can in the Problem Solving forum
“Let''s first inscribe the largest possible square inside the circle https://i.imgur.com/VYR1e8V.png Since the radius of the cylinder is 2, we know that the DIAMETER = 4 https://i.imgur.com/Gg3toPv.png Since we have a RIGHT TRIANGLE, we can apply the Pythagorean Theorem to get: x² + x² = ...”
June 18, 2018
Brent@GMATPrepNow posted a reply to Help!! in the Data Sufficiency forum
“A certain business printer can print 40 characters per second... 40 x 60 = 2400 So, the business printer can print 2400 characters PER MINUTE ..., which is 4 times as fast as an average printer. 2400/4 = 600 So, the average printer can print 600 characters PER MINUTE If an average printer ...”
June 18, 2018
Brent@GMATPrepNow posted a reply to gmat prep in the Problem Solving forum
“n= 1/3 + 1/3^2 + 1/3^3 = 1/3 + 1/9 + 1/27 = 9/27 + 3/27 + 1/27 = 13/27 ≈ 1/2 Answer: C Cheers, Brent”
June 18, 2018
Brent@GMATPrepNow posted a reply to GMAT PREP QUES in the Problem Solving forum
“-----ASIDE--------------------- A lot of integer property questions can be solved using prime factorization. For questions involving divisibility, divisors, factors and multiples, we can say: If N is divisible by k (i.e., N is a multiple of k), then k is "hiding" within the prime ...”
June 18, 2018
Brent@GMATPrepNow posted a reply to gmat prep q in the Problem Solving forum
June 18, 2018
Brent@GMATPrepNow posted a reply to gmat prep q in the Problem Solving forum
“Here''s the full question... 2^(X+Y)²/ 2^(X-Y)² = 2^(X² + 2XY + Y²)/ 2^(X² - 2XY + Y²) = 2^(4XY) = 2^4 = 16 Answer: D Cheers, Brent”
June 18, 2018
Brent@GMATPrepNow posted a reply to If x is a 3–digit number, is x even? in the Data Sufficiency forum
“Target question: Is x even? Given: x is a 3–digit number, Jump to...... Statements 1 and 2 combined There are several values of x that satisfy BOTH statements. Here are two: Case a: x = 222. In this case, the answer to the target question is YES, x IS even Case b: x = 121. In ...”
June 18, 2018
Brent@GMATPrepNow posted a reply to Which of the following is NOT a possible value of in the Problem Solving forum
“When we scan the answer choices, we can see that 1/(4-x) can never equal 0. To see why, take 1/(4-x) = 0 and multiply each side by (4-x) to get: 1 = 0, doesn''t work. Answer: C B) 4/17 Let 1/(4-x) = 4/17 Cross multiply to get: (1)(17) = (4)(4 - x) Expand: 17 = 16 - 4x Subtract 16 ...”
June 18, 2018
Brent@GMATPrepNow posted a reply to Is a positive? in the Data Sufficiency forum
“All values (positive or negative) of a will satisfy the equation a - a = 0 For example, if a = 3, then we get: 3 - 3 = 0 (works!) Conversely, if a = -3, then we get: -3 - (-3) = 0 (works!) And, if a = 0, then we get: 0 - 0 = 0 (works!) Cheers, Brent”
June 18, 2018
Brent@GMATPrepNow posted a reply to Is a positive? in the Data Sufficiency forum
“Target question: Is a positive? Jump straight to.... Statements 1 and 2 combined There are infinitely many values of a that satisfy BOTH statements. Here are two: Case a: a = 1 (this satisfies BOTH statements). In this case, the answer to the target question is YES, a IS positive Case ...”
June 18, 2018
Brent@GMATPrepNow posted a reply to The size of a television screen is given as the length in the Problem Solving forum
“Let x be the length (and width) of the square screen with diagonal 21 The area of the large screen will be x² Let y be the length (and width) of the square screen with diagonal 19 The area of the small screen will be y² Our goal is to find the value of x² - y² Large TV: If we examine ...”
June 18, 2018
beatthegmat started following jdiddy
June 18, 2018
Brent@GMATPrepNow posted a new topic called Challenge question: Each edge of the above cube has length 1 in the Problem Solving forum
“https://i.imgur.com/pCPvPai.png Each edge of the above cube has length 1. If an ant walks from point A to point B along the OUTSIDE of the cube, what is shortest distance the ant must travel? A) √3 B) 2 C) √5 D) √6 E) √7 Answer: C Difficulty level: 700+ Source: ...”
June 17, 2018
Brent@GMATPrepNow posted a reply to Permutations/Combinations in the Problem Solving forum
“Take the task of distributing the 12 books and break it into stages Let''s say the children are named A, B and C Stage 1: Select 4 books to give to child A Since the order in which we select the 4 books does not matter, we can use combinations. We can select 4 books from 12 books in 12C4 ...”
June 16, 2018
Brent@GMATPrepNow posted a reply to Probability in the Problem Solving forum
“First, if P(test) = 1/5, then p(NO test) = 1 - 1/5 = 4/5 NOTE: questions with "at least" are often great candidates for using the complement. That is: P(Event A occurs) = 1 - P(Event A does not occur) So, P(miss at least 1 test) = 1 - P(miss no tests) P(miss no tests) P(miss no ...”
June 16, 2018
Brent@GMATPrepNow posted a reply to Probability in the Problem Solving forum
“P(all 3 are same type) = P(all 3 are tennis OR all 3 are cricket OR all 3 are squash) = P(all 3 are tennis) + P(all 3 are cricket) + P(all 3 are squash) = P(1st is tennis AND 2nd is tennis AND 3rd is tennis) + (1st is cricket AND 2nd is cricket AND 3rd is cricket) + P(1st is squash AND 2nd is ...”
June 16, 2018
Brent@GMATPrepNow posted a reply to w, x, y and z are positive integers such that y < z < in the Data Sufficiency forum
“Target question: What is the value of x? Given: w, x, y and z are positive integers such that y < z < x < w. When w is divided by x, the quotient is y, and the remainder is z. Statement 1: The least common multiple of w and x is 30 There are several values of w and x that ...”
June 15, 2018
Brent@GMATPrepNow posted a reply to Is y = 7? in the Data Sufficiency forum
“Target question: Is y = 7? Statement 1: (x - 4) = 0 This tells us that x = 4, but it provides no information about the value of y Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT Statement 2: (x - 3)(y - 7) = 0 This tells us that EITHER x = 3 OR y ...”
June 15, 2018
Brent@GMATPrepNow posted a reply to In a certain sequence term_1 = 64 in the Problem Solving forum
“Let''s list a few terms and look for a pattern term1 = 64 = 2^8 term2 = (2^8)(2^2) term3 = (2^8)(2^2)(2^3) term4 = (2^8)(2^2)(2^3)(2^4) . . . term8 = (2^8)(2^2)(2^3)(2^4)(2^5)(2^6)(2^7)(2^8) . . . term11 = (2^8)(2^2)(2^3)(2^4)(2^5)(2^6)(2^7)(2^8)(2^9)(2^10)(2^11) So, ...”
June 15, 2018
Brent@GMATPrepNow posted a reply to If |x - 2| = |x + 3|, x could equal in the Problem Solving forum
“There are 3 steps to solving equations involving ABSOLUTE VALUE: 1. Apply the rule that says: If |x| = k, then x = k and/or x = -k 2. Solve the resulting equations 3. Plug solutions into original equation to check for extraneous roots Given: |x - 2| = |x + 3| case a: x - 2 = x + 3 Subtract ...”
June 15, 2018
Brent@GMATPrepNow posted a reply to $\sqrt{16+16}=$ in the Problem Solving forum
June 15, 2018
Brent@GMATPrepNow posted a reply to $\sqrt{16+16}=$ in the Problem Solving forum
“Useful rule: √(xy) = (√x)(√y) So, √(16 + 16) = √(32) = √(16 x 2) = √16 x √2 = 4 x √2 = 4√2 Answer: A Cheers, Brent”
June 15, 2018
Brent@GMATPrepNow posted a reply to If n is the product of the squares of 4 different prime numb in the Problem Solving forum
“-----------ASIDE------------------ If the prime factorization of N = (p^a)(q^b)(r^c) . . . (where p, q, r, etc are different prime numbers), then N has a total of (a+1)(b+1)(c+1)(etc) positive divisors. Example: 14000 = (2^4)(5^3)(7^1) So, the number of positive divisors of 14000 = ...”
June 15, 2018
Brent@GMATPrepNow posted a reply to Is x > 0 ? in the Data Sufficiency forum
“Target question: Is x > 0 ? Let''s go straight to... Statements 1 and 2 combined Statement 1 tells us that x < x² Statement 2 tells us that x < x³ There are several values of x that satisfy BOTH statements. Here are two: Case a: x = 2. Notice that 2 < 2² AND 2 < 2³. ...”
June 14, 2018
Brent@GMATPrepNow posted a reply to If x and y are prime numbers, and n is a positive integer, w in the Data Sufficiency forum
“-------ASIDE---------------- If the prime factorization of N = (p^a)(q^b)(r^c) . . . (where p, q, r, etc are different prime numbers), then N has a total of (a+1)(b+1)(c+1)(etc) positive divisors. Example: 14000 = (2^4)(5^3)(7^1) So, the number of positive divisors of 14000 = (4+1)(3+1)(1+1) ...”
June 14, 2018
June 14, 2018
Brent@GMATPrepNow posted a reply to x and y are integers such that 4x^2 – y^2 +4x + 4y – 3 = in the Problem Solving forum
“Let''s examine the expression in parts 4x² is EVEN for all integer values of x y² not sure 4x is EVEN for all integer values of x 4y is EVEN for all integer values of y 3 is ODD 0 is EVEN So, we get: EVEN – y² + EVEN + EVEN – ODD = EVEN Simplify left side: ODD – y² = EVEN ...”
June 14, 2018
Brent@GMATPrepNow posted a reply to On July 1, 2017, a certain tree was 128 centimeters tall. Ea in the Problem Solving forum
“Let''s create a growth table and look for a pattern year | height in cm 2017: 128 2018: 128(1.5) 2019: 128(1.5)^2 2020: 128(1.5)^3 2021: 128(1.5)^4 2022: 128(1.5)^5 2023: 128(1.5)^6 The tree''s height on July 1, 2023 will be how many centimeters greater than the tree''s height on July ...”
June 14, 2018
Brent@GMATPrepNow posted a reply to The sum of 3 consecutive numbers is definitely: in the Problem Solving forum
“Another approach: Let x = the smallest integer So, x+1 = the next integer And x+2 = the last integer Sum of 3 consecutive numbers = x + (x+1) + (x+2) = 3x + 3 = 3(x+1) As we can see, the sum MUST be a multiple of 3 Or we can say the sum MUST be a divisible by 3 Answer: C ...”
June 13, 2018
Brent@GMATPrepNow posted a reply to N is a 3-digit number, and the sum of its digits is 10. When in the Data Sufficiency forum
“Target question: What is the value of N? Given: N is a 3-digit number, and the sum of its digits is 10. When the digits of N are reversed, the new number is 99 less than N. Let N = wxy, where w, x and y represent the 3 digits in N So, the first equation we can write is: w + x + y = 10 ...”
June 13, 2018
Brent@GMATPrepNow posted a new topic called In a certain sequence term_1 = 64 in the Problem Solving forum
“In a certain sequence, term1 = 64, and for all n > 1, termn = (2^n)(termn-1) What is the value of term11/term8 ? A) 2^3 B) 2^6 C) 2^9 D) 2^27 E) 2^30 Answer: E Difficulty level: 600 - 650 Source: www.gmatprepnow.com * I''ll provide a solution in 2 days”
June 13, 2018
Brent@GMATPrepNow posted a new topic called w, x, y and z are positive integers such that y < z < x < w. in the Data Sufficiency forum
“w, x, y and z are positive integers such that y < z < x < w. When w is divided by x, the quotient is y, and the remainder is z. What is the value of x? (1) The least common multiple of w and x is 30 (2) x³ – 8x² + 12x = 0 Answer: B Difficulty level: 700+ Source: ...”
June 13, 2018
Brent@GMATPrepNow posted a reply to A 75-liter solution of cool-drink is made from 8% jasmine in the Problem Solving forum
“Your solution isn''t quite correct. A 75-liter solution of cool-drink is made from 8% jasmine water. 8% of 75 = (8/100)(75) = 6 So, the 75 liters is comprises of 6 liters of jasmine If 3 liters of jasmine and 12 liters of water were added to the solution.... We adding 15 liters, so the NEW ...”
June 12, 2018
Brent@GMATPrepNow posted a new topic called On July 1, 2017, a certain tree was 128 centimeters tall. Ea in the Problem Solving forum
“On July 1, 2017, a certain tree was 128 centimeters tall. Each year, the tree''s height increases 50%. Given this growth rate, the tree''s height on July 1, 2023 will be how many centimeters greater than the tree''s height on July 1, 2022? A) (2^2)(3^4) B) (2)(3^4) C) (2)(3^5) D) (4)(3^5) ...”
June 12, 2018
Brent@GMATPrepNow posted a reply to tricky challenge question - Is CB || ED? in the Data Sufficiency forum
“Target question: Is CB || ED? Let''s jump straight to.... Statements 1 and 2 combined Statement 1 tells us that ∆ABC and ∆AED are both isosceles triangles Statement 2 tells us that ∠C = ∠E Let''s start with 2 identical isosceles triangles: https://i.imgur.com/IQe4Cwq.png ...”
June 12, 2018
Brent@GMATPrepNow posted a new topic called N is a 3-digit number, and the sum of its digits is 10. When in the Data Sufficiency forum
“N is a 3-digit number, and the sum of its digits is 10. When the digits of N are reversed, the new number is 99 less than N. What is the value of N? (1) The hundreds digit of N is 1 more than its units digit. (2) The tens digit of N is 2 more than its hundreds digit. *solution posted in 2 ...”
June 11, 2018
Brent@GMATPrepNow posted a reply to If n is the sum of the first 50 positive integers, what is t in the Problem Solving forum
“Alternatively, we can use the following formula: Sum of the first k positive integers = (k)(k+1)/2 For example, the sum of the first 10 positive integers = (10)(10 + 1)/2 = 55 So, the sum of the first 50 positive integers = (50)(50 + 1)/2 = (50)(51)/2 = (25)(51) = (5)(5)(3)(17) Answer: ...”
June 11, 2018
Brent@GMATPrepNow posted a reply to If n is the sum of the first 50 positive integers, what is t in the Problem Solving forum
“n = 1 + 2 + 3 + 4 + ...... + 47 + 48 + 49 + 50 Let''s add the values in pairs, starting from the outside and work towards the middle n = (1 + 50) + (2 + 49) + (3 + 48) + . . .. = 51 + 51 + 51 + ..... Since we are adding 50 values (from 1 to 50), we will get 25 PAIRS of values So, n = ...”
June 11, 2018
Brent@GMATPrepNow posted a reply to What is the value of x/3+y/3? in the Data Sufficiency forum
“Target question: What is the value of x/3 + y/3? Statement 1: (x + y)/3 = 6 Nice (and often tested) rule: (a + b)/c = a/c + b/c So, we can rewrite the equation as: x/3 + y/3 = 6 So, the answer to the target question is x/3 + y/3 = 6 Since we can answer the target question with certainty, ...”
June 11, 2018
Brent@GMATPrepNow posted a reply to work in the Problem Solving forum
“Starting point: 3 men, 4 women and 6 children A child does half the work a man does. In other words, 1 child = 1/2 a man This means 6 children = 3 men So, let''s just REPLACE the 6 children with 3 men to get: 6 men and 4 women A woman does double the work a man does In other words, 1 ...”
June 11, 2018
Brent@GMATPrepNow posted a reply to In the above diagram, the circle inscribes the larger in the Problem Solving forum
“Another approach is to use the following fact: For GMAT Problem Solving questions (i.e., questions that are NOT data sufficiency questions), all diagrams are DRAWN TO SCALE, unless stated otherwise. So, we can use this to ESTIMATE the area of the larger triangle. We know the smaller ...”
June 10, 2018
Brent@GMATPrepNow posted a reply to In the above diagram, the circle inscribes the larger in the Problem Solving forum
“We''re told that the area of the smaller triangle is √3 USEFUL FORMULA: Area of an equilateral triangle = (√3)(side²)/4 So, we can write: (√3)(side²)/4 = √3 Divide both sides by √3 to get: (side²)/4 = 1 Multiply both sides by 4 to get: side² = 4 Solve: side = 2 So, each side of ...”
June 10, 2018
Brent@GMATPrepNow posted a reply to John traveled 80% of the way from Yellow-twon to Green- in the Problem Solving forum
“Your solution is great. Another option would be to test the answer choices. Cheers, Brent”
June 10, 2018
Brent@GMATPrepNow posted a new topic called tricky challenge question - Is CB || ED? in the Data Sufficiency forum
“https://i.imgur.com/QY581Gp.png Is CB || ED? (1) ∆ABC and ∆AED are both isosceles triangles (2) ∠C = ∠E”
June 10, 2018
Brent@GMATPrepNow posted a reply to If x > 0, b > a, and 2x + 5 < 3x + 1, then which of in the Problem Solving forum
“Here''s a useful triangle property: https://i.imgur.com/dLnB7G2.png So, if b > a, then we know that 3x + 1 < 4x - 8 We''re also told that 2x + 5 < 3x + 1 So, we can create the following 3-part inequality: 2x + 5 < 3x + 1 < 4x - 8 Subtract 2x from all 3 sides: 5 < x + 1 ...”
June 9, 2018
beatthegmat posted a new topic called Is The GMAT Stopping You From An MBA? in the The Application Process forum
“https://s33.postimg.cc/mgtq5l3jf/gmat.png Not everyone is good at taking tests. Especially when you feel as if your entire career is resting on the results of four hours spent in an airless room with dozens of other people who look cool, calm and collected while you’re sweating through ...”
June 8, 2018
Brent@GMATPrepNow posted a reply to If the sum of the minimum and the maximum of 7 consecutive o in the Problem Solving forum
“One more (longer!) solution. Let x = smallest ODD integer So, x+2 = next (2nd) ODD integer x+4 = next (3rd) ODD integer . . . x + 12 = largest (7th) ODD integer Sum of the minimum and the maximum is 114 So, x + x + 12 = 114 Simplify: 2x + 12 = 114 So, 2x = 102 Solve: x = 51 ...”
June 8, 2018
Brent@GMATPrepNow posted a reply to If x and y are integers, and x/y = 1.64, which in the Problem Solving forum
“Given: x/y = 1.64 Rewrite as: x/y = 164/100 Simplify: x/y = 41/25 So, it''s possible that x = 41 and y = 25 We can also create infinitely many fractions that are EQUIVALENT to 41/25 For example, we can take 41/25 and multiply top and bottom by 2 to get: 82/50 So, it''s possible that x = 82 ...”
June 8, 2018
Brent@GMATPrepNow posted a reply to Train X leaves New York at 1 A.M. and travels east at a in the Problem Solving forum
“Train X leaves at 1 A.M. and Train Z leaves New York at 2 A.M. When they meet at 5:30 A.M., Train X''s travel time will be 4.5 hours, and Train Z''s travel time will be 3.5 hours Also recognize that, when the trains meet, they both will have traveled the same distance. We know that Train X ...”
June 8, 2018
Brent@GMATPrepNow posted a new topic called In the above diagram, the circle inscribes the larger in the Problem Solving forum
“https://i.imgur.com/BywBeDq.png In the above diagram, the circle inscribes the larger equilateral, and it circumscribes the smaller equilateral triangle. If the area of the smaller triangle is √3, what is the area of the larger triangle? A) 9π - 16√3 B) 4√3 C) 8√3 D) 16√3 E) ...”
June 8, 2018
Brent@GMATPrepNow posted a reply to On entering the stadium, cheers greeted them in the Sentence Correction forum
“A. On entering the stadium, cheers greeted them We get: ...cheers greeted them as a sign of universal approval... So, the PEOPLE were a sign of approval? This doesn''t make sense. The CHEERS were a sign of approval. ELIMINATE A ELIMINATE D and E for the same reason. B. On entering the ...”
June 7, 2018
Brent@GMATPrepNow posted a reply to inference in the Critical Reasoning forum
“When answering inference questions on the GMAT, are looking for the answer choice that MUST follow from the premises. So, as we examine the answer choices, we must aggressively eliminate any answer choice that does not necessarily follow from the premises. (A) Individuals who are underweight do ...”
June 7, 2018
Brent@GMATPrepNow posted a reply to One gallon of soft drink is made of 40% orange juice and 60% in the Problem Solving forum
“IMPORTANT CONCEPT: when we combine EQUAL amounts of two mixtures, the concentration of the resulting mixture will be the AVERAGE of the two mixtures. For example, if we combine 1 liter of a 10% salt solution with 1 liter of a 40% salt solution, the RESULTING solution will be 25% salt, since ...”
June 7, 2018
Brent@GMATPrepNow posted a reply to When positive integer N is divided by 18, the remainder is x in the Problem Solving forum
“Let''s examine each statement separately... i) x = 9 and y = 3 Let''s come up with a value of N that satisfies this condition. How about N = 9? 9 divided by 18 = 0 with remainder 9 (i.e., x = 9) ...and 9 divided by 6 = 1 with remainder 3 (i.e., y = 3) Perfect, statement i is TRUE Check the ...”
June 7, 2018
Brent@GMATPrepNow posted a new topic called If x > 0, b > a, and 2x + 5 < 3x + 1, then which of the in the Problem Solving forum
“https://i.imgur.com/jteIDVs.png If x > 0, b > a, and 2x + 5 < 3x + 1, then which of the following COULD be a value of x? i) 4.39 ii) 7.17 iii) 9.27  A) i and ii only B) ii and iii only C) i and iii only D) iii only E) i, ii and iii Answer: D Difficulty level: 600 – ...”
June 7, 2018
Brent@GMATPrepNow posted a reply to In the coordinate plane, is the x-intercept of the line ax + in the Data Sufficiency forum
“Target question: Is the x-intercept less than 0? This is a good candidate for rephrasing the target question. Aside: Here’s a video with tips on rephrasing the target question: The x-intercept is the point where a line crosses the x-axis. At this point, the y-coordinate is ZERO So, the ...”
June 6, 2018
Brent@GMATPrepNow posted a reply to $\frac{49^2-35^2}{14}=$ in the Problem Solving forum
“My bad. Here''s the video for squaring numbers that end in 5: https://www.gmatprepnow.com/module/gmat-powers-and-roots/video/1024 Cheers, Brent”
June 6, 2018
Brent@GMATPrepNow posted a reply to How many of the positive divisors of 120 are also multiples in the Problem Solving forum
“Alternatively, we can just list all divisors in an systematic fashion. We''ll list the divisors in PAIRS of numbers that have a product of 120: 1 and 120 2 and 60 3 and 40 4 and 30 5 and 24 6 and 20 8 and 15 10 and 12 DONE Scanning our list, the multiples of 4 are in red There are 7 ...”
June 6, 2018
Brent@GMATPrepNow posted a reply to Rene aerns $8.50 per hour on days other than Sundays and in the Problem Solving forum “Your solution is great. Here''s one small tip for reducing your calculations by one. Once we know that Rene''s earnings = (32)(8.5) + (8)(17), we can use a nice technique called "Multiplication by Halving and Doubling" It goes like this: AB = (A/2)(2B) For example: (18)(3.5) = ...” June 6, 2018 Brent@GMATPrepNow posted a new topic called If x and y are integers, and x/y = 1.64, which in the Problem Solving forum “If x and y are integers, and x/y = 1.64, which of the following CANNOT be a value of x? A) -656 B) -82 C) 123 D) 205 E) 288 Answer: E Difficulty level: 550 – 600 Source: www.gmatprepnow.com” June 6, 2018 beatthegmat posted a new topic called Your Business School Application: 4 Things to Do Right Now in the The Application Process forum “Congratulations on the decision to pursue a professional business degree! Are you wondering where to start? Applying to MBA and specialized master’s programs requires careful planning and preparation. Checking these first tasks off your list can help put you on the path to success. 1. Know your ...” June 5, 2018 Brent@GMATPrepNow posted a reply to 30^20 – 20^20 is divisible by all in the Problem Solving forum “Here are some useful divisibility rules: 1. If integers A and B are each divisible by integer k, then (A + B) is divisible by k 2. If integers A and B are each divisible by integer k, then (A - B) is divisible by k 3. If integer A is divisible by integer k, BUT integer B is NOT divisible by ...” June 5, 2018 Brent@GMATPrepNow posted a new topic called When positive integer N is divided by 18, the remainder is x in the Problem Solving forum “When positive integer N is divided by 18, the remainder is x. When N is divided by 6, the remainder is y. Which of the following are possible values of x and y? i) x = 9 and y = 3 ii) x = 16 and y = 2 iii) x = 13 and y = 7 A) i only B) i and ii only C) i and iii only D) ii and iii only ...” June 5, 2018 Brent@GMATPrepNow posted a reply to A straight line has a slope of 1/2 and a y-intercept of in the Problem Solving forum “Given this information, we can write the equation for the line in slope y-intercept form, y = mx + b, where m = the slope and b = the y-intercept We''re told that the slope is 1/2 and the y-intercept is -2 So, the equation of the line is: y = (1/2)x + (-2) Simplify to get: y = (1/2)x - 2 ...” June 5, 2018 Brent@GMATPrepNow posted a reply to If -10 < k < 10, is k > 0? in the Data Sufficiency forum “Target question: Is k > 0 Given: -10 < k < 10 Statement 1: 1/k > 0 In other words, 1/k is POSITIVE Since 1 is positive, we can write: POSITIVE/k = POSITIVE From this, we can conclude that k must be POSITIVE So, the answer to the target question is YES, it is the case that ...” June 5, 2018 Brent@GMATPrepNow posted a reply to If 2x = 3y = 10, then 12xy = ? in the Problem Solving forum “Mitch has already demonstrated the fastest/best approach, but even if you didn''t see that approach, we can always solve the question by first solving the equations for x and y. Here''s what I mean..... GIVEN: 2x = 10 Solve to get: x = 5 GIVEN: 3y = 10 Solve to get: y = 10/3 So, 12xy ...” June 5, 2018 Brent@GMATPrepNow posted a reply to When x and n are positive integers, if x^{2n}>(3x)^n, whi in the Problem Solving forum “Let''s find some values that satisfy the given condition that x^{2n} > (3x)^n How about x = 4 and n = 1. When we plug in these values we get: 4^2 > 12^1, which simplifies to 16 > 12. PERFECT. Which of the following must be true? A. x>3 One possible solution is n = 4. This ...” June 4, 2018 Brent@GMATPrepNow posted a reply to progressions in the Problem Solving forum “What''s the source of this question? It''s very un-GMAT-like. First, students aren''t required to know what an A.P. is. Second, {19, 19/5, 87/5,...} this is not an arithmetic progression (A.P.). Third, what do you mean by "maximum sum"? Are you thinking of an infinite GEOMETRIC ...” June 4, 2018 Brent@GMATPrepNow posted a reply to A certain team consists of 4 professors and 6 teaching in the Problem Solving forum “When we see a counting question involving "at least", we should consider using the nice rule: Total number of outcomes that FOLLOW a rule = (TOTAL number of outcomes that IGNORE the rule) - (number of outcomes that BREAK the rule) Here, we have: Total number of teams with AT LEAST one ...” June 4, 2018 Brent@GMATPrepNow posted a reply to progressions in the Data Sufficiency forum “Please note that the GMAT test-makers don''t assume that students know what an arithmetic progression is. In the past, when they''ve used the term "arithmetic sequence", they have also defined the term. Cheers, Brent” June 4, 2018 Brent@GMATPrepNow posted a reply to If m = 0.008163 and M the decimal obtained by rounding m to in the Problem Solving forum “Given: m = 0.008163 The digit 1 is in ten thousandth place of 0.008163 Since next digit (in the hundred thousandth position) is greater than 4, we must ROUND UP So, when we round 0.008163 to the nearest to ten thousandth, we get: 0.0082 In other words, M = 0.0082 So, M + m = 0.0082 + ...” June 4, 2018 Brent@GMATPrepNow posted a reply to If P, Q, and R are distinct positive digits and the product in the Problem Solving forum “That''s a perfect approach. The hardest part is looking for two 2-digit numbers that have a product of 221!! Cheers, Brent” June 4, 2018 Brent@GMATPrepNow posted a reply to On a road trip, Kip drove one-quarter the distance at an ave in the Problem Solving forum “Since we aren''t told the total distance, let''s assign a nice value to the distance. Let''s say 32 miles = TOTAL distance. So, each quarter = 8 miles Average speed = total distance/total travel time So, we must find the travel time for EACH QUARTER and add them together. Time = ...” June 4, 2018 Brent@GMATPrepNow posted a reply to If 2/a+3/a+4/a is an integer, which of the following must in the Problem Solving forum “That''s a perfect approach. 2/a+3/a+4/a = 9/a. So, if 2/a+3/a+4/a is an integer, then 9/a must be an integer as well. Another approach would be to use the fact that the question asks "Which of the following must also be an integer?" So, first find a value of a so that 2/a+3/a+4/a ...” June 4, 2018 Brent@GMATPrepNow posted a new topic called 30^20 – 20^20 is divisible by all in the Problem Solving forum “30^20 – 20^20 is divisible by all of the following values, EXCEPT: A) 10 B) 25 C) 40 D) 60 E) 64 Answer: D Difficulty level: 600 – 650 Source: www.gmatprepnow.com” June 4, 2018 Brent@GMATPrepNow posted a new topic called On a road trip, Kip drove one-quarter the distance at an ave in the Problem Solving forum “On a road trip, Kip drove one-quarter the distance at an average speed of v miles per hour, one-quarter the distance at an average speed of 2v miles per hour, one-quarter the distance at 4v miles per hour, and one-quarter the distance at 8v miles per hour. In terms of v, what was Kip’s average ...” June 3, 2018 Brent@GMATPrepNow posted a reply to inequality in the Data Sufficiency forum “Target question: Is the product cd positive? Statement 1: 3c = -8d³ Divide both sides by d to get: 3c/d = -8d² Divide both sides by 3 to get: c/d = -8d²/3 Rewrite as: c/d = (-8/3)(d²) Since d² is greater than or equal to zero for all values of d, and since -8/3 is NEGATIVE, we can ...” June 3, 2018 Brent@GMATPrepNow posted a reply to Last year the price per share of Stock X increased by k % in the Problem Solving forum “One approach is to plug in values. Let$100 be the original price per share of Stock X Choose a "nice" value for k. How about k = 200 So, after a 200% increase, the new price per share = $300 Let$100 be the original earnings per share of Stock X Choose a "nice" ...”
June 3, 2018
Brent@GMATPrepNow posted a new topic called What is the volume of the largest cube that can in the Problem Solving forum
“What is the volume of the largest cube that can fit inside a cylinder with radius 2 and height 3? A) 9 B) 8√2 C) 16 D) 16√2 E) 27 Answer: D Difficulty level: 650 – 700 Source: www.gmatprepnow.com”
June 2, 2018
Brent@GMATPrepNow posted a reply to Set X contains 10 consecutive integers. If the sum of the in the Problem Solving forum
“-------ASIDE------------------------------------------- Notice that we can write the first 10 consecutive integers as follows: 1, 2, 3, 4, 5, (1 + 5), (2 + 5), (3 + 5), (4 + 5), (5 + 5) So, the sum of the first 5 integers = 1 + 2 + 3 + 4 + 5 The sum of the last 5 integers = (1 + 5) + (2 + ...”
June 2, 2018
Brent@GMATPrepNow posted a reply to If 2^x = 5 and 4^y = 20, what is the in the Problem Solving forum
“Here''s a totally different approach: GIVEN: 2^x = 5 2^2 = 4 and 2^3 = 8 Since 5 is BETWEEN 4 and 8, we know that x is BETWEEN 2 and 3. From here, we can estimate. Since 5 is closer to 4 than it is to 8, we know that x will be closer to 2 than it is to 3. Let''s say that x ≈ 2.3 ...”
June 2, 2018
Brent@GMATPrepNow posted a reply to If 2^x = 5 and 4^y = 20, what is the in the Problem Solving forum
“There are several approaches we can take. Here''s the algebraic approach: Given: 2^x = 5 and 4^y = 20 Take second equation and rewrite 4 as 2² to get: (2²)^y = 20 Simplify to get: 2^(2y) = 20 We now have: 2^(2y) = 20 2^x = 5 This means we can write: 2^(2y)/2^x = 20/5 Simplify: 2^(2y ...”
June 2, 2018
Brent@GMATPrepNow posted a reply to If x^2-5x+6=2|x-1|, what is the product of all in the Problem Solving forum
“Your approach is perfect. HOWEVER, once you determine that the solutions are x = 1, x = 3 and x = 5, you must then plug those values back into the original equation (x² - 5x + 6 = 2 - |x - 1| ) to identify any EXTRANEOUS roots. Let''s do that x = 1 Plug into the original equation to get: ...”
June 1, 2018
Brent@GMATPrepNow posted a reply to A car travels from point A to B. The average speed of the in the Problem Solving forum
“There''s a bit of ambiguity here. If the first half of the trip is spent at one speed, and the second half is spent at another speed, are we referring to half the total DISTANCE, or half the total TIME. For example, if it takes 10 hours to drive 200 miles, some people might refer to the first ...”
June 1, 2018
Brent@GMATPrepNow posted a new topic called If 2^x = 5 and 4^y = 20, what is the in the Problem Solving forum
“If 2^x = 5 and 4^y = 20, what is the value of x in terms of y? A) y – 2 B) (y + 1)/2 C) 2y – 2 D) y/2 – 2 E) 2y + 2 Answer: C Difficulty level: 600 – 650 Source: www.gmatprepnow.com”
June 1, 2018
Brent@GMATPrepNow posted a reply to Is integer x odd? in the Data Sufficiency forum
“Target question: Is integer x odd? Statement 1: 2x + 1 is odd Since 2x + 1 is ODD for any integer value, this statement doesn''t tell us anything. To understand what I mean, consider these two cases that satisfy statement 1: Case a: x = 1. Here, 2x + 1 = 2(1) + 1 = 3, which is odd. In ...”
June 1, 2018
Brent@GMATPrepNow posted a reply to Today Jim is twice as old as Fred, and Sam is 2 years in the Problem Solving forum
“TODAY''S AGES Today Jim is twice as old as Fred, and Sam is 2 years younger than Fred. Let x = Fred''s age TODAY So, 2x = Jim''s age TODAY And x - 2 = Sam''s age TODAY AGES FOUR YEARS AGO Let''s first determine Jim''s age and Sam''s age FOUR YEARS AGO If 2x = Jim''s age TODAY, then 2x - 4 ...”
June 1, 2018
beatthegmat started following pgupta
June 1, 2018
Brent@GMATPrepNow posted a reply to A data set consists of three integers. What is the standard in the Data Sufficiency forum
“Target question: What is the standard deviation of the 3-integer data set? Statement 1: The average (arithmetic mean) and the median are both 3 Let''s TEST some values. There are several sets that satisfy statement 1. Here are two: Case a: {3, 3, 3}. Notice that the median and mean both ...”
June 1, 2018
Brent@GMATPrepNow posted a reply to ratios in the Problem Solving forum
“I think the fast way is to plug in some nice numbers. Since the two pieces of information regarding the night shift are related to the information regarding the day shift, let''s assign some nice values to the DAY shift. Number of workers Day shift: 5 workers (this is an easy number to find ...”
May 31, 2018
Brent@GMATPrepNow posted a new topic called J = x rounded to the nearest TENTH, and K = x rounded to the in the Problem Solving forum
“J = x rounded to the nearest TENTH, and K = x rounded to the nearest THOUSANDTH. If 0 < x < 1, what is the greatest possible value of J – K? A) 0.005 B) 0.0055 C) 0.05 D) 0.0505 E) 0.0555 Answer: C Difficulty level: 650 – 700 Source: www.gmatprepnow.com”
May 31, 2018
Brent@GMATPrepNow posted a reply to If each of the 4 circles above has radius 1, what in the Problem Solving forum
“Here''s a different approach: Let''s place a square around just one of the circles https://i.imgur.com/xuhL6Te.png Notice that the shaded area IN the square represents 1/4 of the TOTAL shaded area in the diagram. https://i.imgur.com/NrpovG1.png This means that the shaded area in ...”
May 31, 2018
Brent@GMATPrepNow posted a reply to $\frac{49^2-35^2}{14}=$ in the Problem Solving forum
“Vincen has demonstrated the approach I would have used. But, for "fun," here''s another approach. First, you need to know a nice trick for squaring numbers that end in 5 (the trick takes 2 minutes to learn, and then you can perform calculations like 65² and 35² in 5 seconds. Here''s ...”
May 31, 2018
Brent@GMATPrepNow posted a reply to Is 0.4 < x < 0.8? in the Data Sufficiency forum
“Target question: Is 0.4 < x < 0.8? Statement 1: 407x < 376 Divide both sides of the inequality by 407 to get: x < 376/407 Convert to a decimal to get: x < 0.92 There are several values of x that satisfy statement 1. Here are two: Case a: x = 0.6. In this case, the answer ...”
May 31, 2018
Brent@GMATPrepNow posted a reply to Is x+y > 0? in the Data Sufficiency forum
“Target question: Is x+y > 0? Statement 1: x > y Let''s TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 2 and y = 1 (this satisfies the condition that x > y). In this case, x + y = 2 + 1 = 3. So, the answer to the target ...”
May 31, 2018
Brent@GMATPrepNow posted a reply to If [x] is the greatest integer less than or equal to x, what in the Problem Solving forum
“, not 3 Cheers, Brent”
May 30, 2018
Brent@GMATPrepNow posted a reply to If the distances between each pair of consecutive ticks are in the Problem Solving forum
“If the distances between each pair of consecutive ticks are equal, we can write: 2^11 - 2^10 = x - 2^11 We must solve this equation for x.... Add 2^11 to both sides: 2^11 + 2^11 - 2^10 = x Combine the two 2^11''s to get: 2(2^11) - 2^10 = x Rewrite 2 as 2^1 to get: (2^1)(2^11) - 2^10 = x ...”
May 30, 2018
Brent@GMATPrepNow posted a new topic called Challenge question: On the x-y coordinate plane, lines j and in the Data Sufficiency forum
“Challenge question On the x-y coordinate plane, lines j and k intersect at one point. If the equation of line j is bx + ay = 5, and the equation of line k is 2bx - 3ay = -5, what is the value of a + b? (1) Lines j and k intersect at (1, -3). (2) a - b = -3 Answer A Difficulty ...”
May 30, 2018
Brent@GMATPrepNow posted a reply to For what value of x are the mode, the median and the average in the Problem Solving forum
“I sincerely doubt that there''s a better (i.e., faster) approach than the one you describe. One option would be to test the answer choices, but your approach is likely faster. The key concept (which you have identified) is that the mode MUST be 60, since we already have two 60''s. Cheers, ...”
May 30, 2018
Brent@GMATPrepNow posted a reply to If x and y are positive integers less than 10, which in the Problem Solving forum
“When I scan the statements, I see that ii and iii look easier, so I''ll start with those. ii) y√x = x√y We can quickly see that, if x = y, then this statement is TRUE. For example, if x = 1 and y = 1, we get 1√1 = 1√1, which is true. So, statement ii COULD be true. Check the ...”
May 30, 2018
Brent@GMATPrepNow posted a reply to Is the positive integer P a multiple of 11 [A] P = M+N in the Data Sufficiency forum
“Target question: Is P a multiple of 11 Statement 1: P = M+N where M and N are integers Definitely NOT SUFFICIENT Statement 2: M is divisible by 11 and N is not divisible by 11 Since there''s no information about P, there''s no way to answer the target question Statement 2 is NOT ...”
May 30, 2018
Brent@GMATPrepNow posted a reply to Which of the following fractions has the greatest value? (A in the Problem Solving forum
“We might also make things easier by getting rid of the fractions by multiplying all of the values by the lowest common denominator, which is (3^4)(5^5) let'' s do this... (A) 1/(3^2)(5^2) x (3^4)(5^5) = (3^2)(5^3) = (9)(125) (B) 2/(3^2)(5^2) x (3^4)(5^5) = (2)(3^2)(5^3) = (2)(9)(125) (C) ...”
May 30, 2018
Brent@GMATPrepNow posted a reply to Mode in the Problem Solving forum
“This comes down to the distinction between "the mode" and "a mode" The mode of a set of 4 positive integers is 7. This suggests that there is only 1 mode. ASIDE: In the set {1, 2, 4, 4}, there''s one mode: 4 In the set {3, 3, 4, 4}, there are two modes: 3 and 4 In the ...”
May 29, 2018
Brent@GMATPrepNow posted a new topic called If each of the 4 circles above has radius 1, what in the Problem Solving forum
“https://i.imgur.com/bzRq3H2.png If each of the 4 circles above has radius 1, what is the area of the shaded region? A) 1 – π/4 B) 2 – π/4 C) 2 – π/2 D) 4 – π E) 4 – 2π Answer: D Difficulty level: 700+ Source: www.gmatprepnow.com”
May 29, 2018
Brent@GMATPrepNow posted a reply to If x is a positive integer, which of the following COULD in the Problem Solving forum
“There''s a triangle property that says: (length of LONGEST side) < (SUM of the other two lengths) So, for example, 2, 3, 6 CANNOT be the lengths of sides in a triangle, because 6 > 2 + 3 i) x, 2x + 2, x + 2 Since x is a positive integer, we can see that 2x+2 will be the LONGEST side. ...”
May 28, 2018
Brent@GMATPrepNow posted a reply to If 52x + 604 = 1400 and 151 + 13y in the Problem Solving forum
“The key here is to avoid solving the two equations for x and y. We can do this by recognizing that each term in the equation 52x + 604 = 1400 is 4 times each term in the equation 151 + 13y = 350 For example, (4)(151) = 604 And (4)(13) = 52 And (4)(350) = 1400 So, if we take 151 + 13y = ...”
May 28, 2018
Brent@GMATPrepNow posted a new topic called If x and y are positive integers less than 10, which in the Problem Solving forum
“If x and y are positive integers less than 10, which of the following COULD be true? i) √x + √y = √(x + y) ii) y√x = x√y iii) √x - √y = √(x - y) A) i only B) i and ii only C) i and iii only D) ii and iii only E) i,ii and iii Answer: D Difficulty level: 600 – 650 ...”
May 28, 2018
Brent@GMATPrepNow posted a reply to If [x] is the greatest integer less than or equal to x in the Problem Solving forum
“Here are some related questions to practice with: https://www.beatthegmat.com/is-the-greatest-integer-less-than-or-equal-to-the-t299030.html https://www.beatthegmat.com/denotes-the-least-integer-greater-than-or-equal-to-x-t276815.html ...”
May 28, 2018
Brent@GMATPrepNow posted a reply to A soda machine sells both bottles and cans, and no other in the Problem Solving forum
“Let B = # of bottles sold Let C = # of cans sold If on one day, the soda machine sold 250 total beverages... We can write: B + C = 250 ...and yielded $315. So: 1.5B + 0.75C = 315 We can eliminate the decimals by multiplying both sides by 4 to get: 6B + 3C = 1260 How many more bottles ...” May 28, 2018 Brent@GMATPrepNow posted a reply to Are x and y both positive? in the Data Sufficiency forum “Target question: Are x and y both positive? Statement 1: 2x - 2y = 1 There are several pairs of numbers that satisfy this condition. Here are two: Case a: x = 1 and y = 0.5, in which case x and y are both positive Case b: x = -0.5 and y = -1, in which case x and y are not both positive ...” May 28, 2018 Brent@GMATPrepNow posted a new topic called If 52x + 604 = 1400 and 151 + 13y in the Problem Solving forum “If 52x + 604 = 1400 and 151 + 13y = 350, what is the value of x – y? A) -11/13 B) -11/52 C) 0 D) 11/52 E) 11/13 Answer: C Difficulty level: 550 – 600 Source: www.gmatprepnow.com” May 27, 2018 Brent@GMATPrepNow posted a new topic called If x is a positive integer, which of the following COULD in the Problem Solving forum “If x is a positive integer, which of the following COULD represent the lengths of the 3 sides of a triangle? i) x, 2x + 2, x + 2 ii) 2x, 3x, 2x - 7 i) x/2, x/6, x/4 A) i only B) ii only C) iii only D) i and ii only E) ii and iii only Answer: B Difficulty level: 600 – 650 Source: ...” May 26, 2018 Brent@GMATPrepNow posted a reply to subject-verb agreement in the Sentence Correction forum “This is a tricky question because the subject appears AFTER the verb. In most sentences, the verb appears after the subject. Example: Yesterday, Jane bought five acres of ocean floor. The primary verb phrase is has/have grown. To determine the subject that corresponds with this ...” May 26, 2018 Brent@GMATPrepNow posted a reply to If x, y and z are different positive integers, and y is the in the Problem Solving forum “Let''s examine each statement separately... i) y < x If y is the greatest common divisor of x, y and z, we can also say that y is a divisor of x IMPORTANT CONCEPT: The divisors of a number are always less than or equal to that number. For example, the divisors of 10 are {1, 2, 5, 10). So, ...” May 26, 2018 Brent@GMATPrepNow posted a reply to A set has exactly five consecutive positive integers in the Problem Solving forum “What''s the source of this question? It seems very un-GMAT-like to "round" 16 2/3 to 16.4 without some kind of language that suggests we''re looking for the best APPROXIMATE answer.” May 26, 2018 Brent@GMATPrepNow posted a reply to If Lucy walks to work at a rate of 4 miles per hour in the Problem Solving forum “A quick approach is to assign a nice value to the distance from home to work. That is, we want a distance that works well with the two speeds (4 mph and 6 mph) Let''s say the distance from home to work = 12 miles Time TO work = distance/speed = 12/4 = 3 hours Time FROM work = distance/speed = ...” May 25, 2018 Brent@GMATPrepNow posted a reply to Joe’s restaurant has exactly 3 items on its menu in the Data Sufficiency forum “Target question: Can the restaurant make at least 100 meals? Statement 1: Each Prawns Only meal requires 15 prawns The restaurant has 592 prawns. Before calculating 592/15, we can see that, IF the restaurant had 600 prawns, then we could make 40 Prawns Only meals. Since there are 592 ...” May 25, 2018 Brent@GMATPrepNow posted a reply to Solution X is 30% alcohol by volume, solution Y is 10% in the Problem Solving forum “We can avoid tedious calculations by creating this mixture in parts First combine 20 gallons of solution Y (10% alcohol) with 20 gallons of solution Z (40% alcohol) Since we have EQUAL volumes of each solution, the percentage of alcohol in the resulting mixture will be the AVERAGE of the two ...” May 25, 2018 Brent@GMATPrepNow posted a reply to If 0 < x < y, then which of the following MUST be true in the Problem Solving forum “Let''s examine each statement individually: A) (x + 2)/(y + 2) > x/y Since y is POSITIVE, we can safely take the given inequality and multiply both sides by y to get: (y)(x+2)/(y+2) > x Also, if y is POSITIVE, then (y+2) is POSITIVE, which means we can safely multiply both sides by (y+2) ...” May 25, 2018 Brent@GMATPrepNow posted a reply to Which of the following leads to the correct mathematical in the Problem Solving forum “------ASIDE----------------------- When we want to arrange a group of items in which some of the items are identical, we can use something called the MISSISSIPPI rule. It goes like this: If there are n objects where A of them are alike, another B of them are alike, another C of them are alike, ...” May 25, 2018 Brent@GMATPrepNow posted a reply to Mrs. Jones divided$120 evenly among her children. Tom, the in the Problem Solving forum
“Let x = # children that Mrs. Jones has This means x-1 = # of Tom''s siblings. If Tom gives each sibling $6, the total amount that Tom gave to siblings = 6(x - 1) AFTER giving$6 to each sibling, Tom had $12 remaining. So, BEFORE he gave away the money, the amount Tom had = 12 + 6(x - 1) = 12 ...” May 25, 2018 Brent@GMATPrepNow posted a reply to If x = m − 1, which of the following is true when m = 1/2? in the Problem Solving forum “Given: x = m - 1 So, if m = 1/2, then x = 1/2 - 1 = -1/2 Or we can say that x = -0.5 So, x^0 = (-0.5)^0 = 1 x^1 = (-0.5)^1 = -0.5 x^2 = (-0.5)^2 = 0.25 x^3 = (-0.5)^3 = -0.125 The biggest value (1) is for x^0 The next biggest value (0.25) is for x^2 The next value (-0.125) is for x^3 ...” May 25, 2018 Brent@GMATPrepNow posted a reply to Is the product pqr divisible by 12? in the Data Sufficiency forum “Target question: Is the product pqr divisible by 12? It certainly LOOKS like the correct answer is C. However, we are not told whether ALL of the numbers (p, q and r ) are integers. Sure, statements 1 and 2 indirectly tell us that p and q are divisible by 3 and 4, but r may or may not be an ...” May 25, 2018 beatthegmat posted a reply to Delete my account in the Suggestions and Feedback forum “Hi sophylaelin, Your account has been deleted. Best, The BeatTheGMAT Team” May 25, 2018 beatthegmat posted a reply to Delete Account in the Suggestions and Feedback forum “Hi Commoditybull, Your account has been deleted. Best, The BeatTheGMAT Team” May 25, 2018 Brent@GMATPrepNow posted a reply to If x and y are positive integers, and 4x is the least in the Problem Solving forum “Let''s find some values for x and y that satisfy the given information and see what happens.... If x = 3 and y = 4, then the least common multiple of x and y is 12. Notice that 12 = 4x, so x = 3 and y = 4 work perfectly. Now let''s plug x = 3 and y = 4 into the statements... i) 3 is the ...” May 23, 2018 Brent@GMATPrepNow posted a reply to If x and y are integers, and in the Data Sufficiency forum “Target question: What is the value of x? Given: x and y are non-zero integers, and When we see this given information, we should be thinking of a few different ways for the equation to hold true. For example, if x = 1, then (-x)^x = (-1)^1 = -1. What value of y is necessary for y^y to ...” May 23, 2018 Brent@GMATPrepNow posted a new topic called Solution X is 30% alcohol by volume, solution Y is 10% in the Problem Solving forum “Solution X is 30% alcohol by volume, solution Y is 10% alcohol by volume, and solution Z is 40% alcohol by volume. If 41 gallons of solution X, 20 gallons of solution Y, and 20 gallons of solution Z are combined, which of the following best approximates the percentage of alcohol in the resulting ...” May 23, 2018 Brent@GMATPrepNow posted a reply to If wxy ≠ 0, does x = y? in the Data Sufficiency forum “Target question: Does x = y? Given: wxy ≠ 0 IMPORTANT: When I scan the two statements, I can see that this question is testing us on our knowledge about when we can conclude that two exponents are equal. For statement 1, many students will conclude that, if w^x = w^y, then it must be ...” May 23, 2018 Brent@GMATPrepNow posted a reply to What is the sum of the areas of two squares with sides of in the Problem Solving forum “Area of square = (length of one side)² Area of square with side of length 1 = 1² = 1 Area of square with side of length 3 = 3² = 9 Sum of areas = 1 + 9 = 10 Answer: D Cheers, Brent” May 23, 2018 Brent@GMATPrepNow posted a new topic called Joe’s restaurant has exactly 3 items on its menu in the Data Sufficiency forum “Joe’s restaurant has exactly 3 items on its menu: Prawns Only meal, Steak Only meal, and Steak & Prawns meal. If the kitchen has 592 prawns and 30 pounds of steak, can it make at least 100 meals? (1) Each Prawns Only meal requires 15 prawns (2) Each Steak Only meal requires 0.62 pounds ...” May 22, 2018 Brent@GMATPrepNow posted a new topic called If x, y and z are different positive integers, and y is the in the Problem Solving forum “If x, y and z are different positive integers, and y is the greatest common divisor of x, y and z, which of the following MUST be true? i) y < x ii) the greatest common divisor of x and z is greater than y iii) the greatest common divisor of x and y is y A) ii only B) i and ii only C) i ...” May 22, 2018 Brent@GMATPrepNow posted a reply to If p is a positive integer, is p even? in the Data Sufficiency forum “Target question: Is p EVEN? ASIDE: Another way to handle statement 2 is to apply a useful rule: 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 ...” May 22, 2018 Brent@GMATPrepNow posted a reply to How many gallons of water must be mixed with 1 gallon in the Problem Solving forum “Let x = the volume (in gallons) of water that must be added to the existing mixture. We have 1 gallon of the EXISTING mixture, which is 15% salt. 15% of 1 = 0.15 So, the EXISTING mixture contains 0.15 gallons of salt When we add x gallons of water to the existing mixture, the NEW mixture has ...” May 22, 2018 Brent@GMATPrepNow posted a reply to A jar contains 6 red marbles and 9 blue marbles. If Evelyn in the Problem Solving forum “P(both are same color) = P(1st marble is red AND 2nd marble is red OR 1st marble is blue AND 2nd marble is blue) = x P(2nd marble is red)] + x P(2nd marble is blue)] = x 5/14] + x 8/14] = x 5/14] + x 8/14] = 10/70 + 24/70 = 34/70 = 17/35 Answer: D Cheers, Brent” May 21, 2018 Brent@GMATPrepNow posted a reply to If x = 3y = 4z, which of the following must equal 6x ? in the Problem Solving forum “Let''s examine each statement I. 18y Given: x = 3y Multiply both sides by 6 to get: 6x = 18y Perfect! Statement I is TRUE Check the answer choices.....ELIMINATE B and C since they state that statement I is not true. II. 3y + 20z Given: x = 3y Also, since x = 4z, we can multiply both ...” May 21, 2018 Brent@GMATPrepNow posted a reply to If A is a prime number, what is the value of A? in the Data Sufficiency forum “Target question: What is the value of A? Given: A is a prime number Statement 1: 0 < A < 10 Let''sTEST some values. There are several values of A that satisfy statement 1. Here are two: Case a: A = 2 Case b: A = 3 Since we cannot answer the target question with certainty, ...” May 21, 2018 Brent@GMATPrepNow posted a reply to If p is a positive integer, is p even? in the Data Sufficiency forum “Target question: Is p even? Statement 1: p divided by 3 leaves a remainder of 1 In other words, p is 1 greater than some multiple of 3 There are several values of p that satisfy this condition. Here are two: Case a: p = 4. In this case, the answer to the target question is YES, p is even ...” May 21, 2018 Brent@GMATPrepNow posted a new topic called If x and y are positive integers, and 4x is the least in the Problem Solving forum “If x and y are positive integers, and 4x is the least common multiple of x and y, which of the following MUST be true? i) x is the greatest common divisor of x and y ii) x = y/4 iii) x is a multiple of 4 A) i only B) ii only C) iii only D) ii and iii only E) none Answer: E Difficulty ...” May 21, 2018 Brent@GMATPrepNow posted a new topic called If x and y are integers, and in the Data Sufficiency forum “If x and y are non-zero integers, and (-x)^x = y^y, what is the value of x? (1) x + y = 0 (2) x is odd Answer: E Difficulty level: 650 – 700 Source: www.gmatprepnow.com” May 21, 2018 Brent@GMATPrepNow posted a reply to On Monday, Karen had S dollars in her savings account in the Problem Solving forum “Monday S dollars in savings account C dollars in checking account Tuesday: Karen transferred half of the money in her savings account to her checking account Amount in savings account = 0.5S Amount in checking account = C + 0.5S Wednesday: Karen transferred 20% of the money in her checking ...” May 21, 2018 Brent@GMATPrepNow posted a reply to Is 2 < xy < 20? in the Data Sufficiency forum “Target question: Is 2 < xy < 20? Statement 1: -2 < x < 4 Since we have no information about the value of y, there''s no way to the target question with certainty. So, statement 1 is NOT SUFFICIENT Statement 2: -1 < y < 5 There are several values of x and y that ...” May 21, 2018 Brent@GMATPrepNow posted a new topic called Is 2 < xy < 20? in the Data Sufficiency forum “Is 2 < xy < 20? (1) -2 < x < 4 (2) -1 < y < 5 Answer: E Difficulty level: 450 - 500 Source: www.gmatprepnow.com” May 20, 2018 Brent@GMATPrepNow posted a new topic called On Monday, Karen had S dollars in her savings account in the Problem Solving forum “On Monday, Karen had S dollars in her savings account and C dollars in her checking account. On Tuesday, Karen transferred half of the money in her savings account to her checking account. On Wednesday, Karen transferred 20% of the money in her checking account to her savings account, at which point ...” May 20, 2018 Brent@GMATPrepNow posted a reply to m and n are positive integers. If mn + 2m + n + 1 is even, in the Problem Solving forum “Here''s a different solution: Since m and n can each be either even or odd, there are 4 possible cases to consider: case a) m is EVEN and n is EVEN case b) m is ODD and n is EVEN case c) m is EVEN and n is ODD case d) m is ODD and n is ODD Now let''s test each case as we examine mn + 2m + ...” May 19, 2018 Brent@GMATPrepNow posted a reply to m and n are positive integers. If mn + 2m + n + 1 is even, in the Problem Solving forum “There are several ways to approach this question. Here''s one approach: First recognize that mn + 2m + n + 1 is ALMOST factorable. If the expression were mn + 2m + n + 2, then we COULD factor it. Next, recognize that, if mn + 2m + n + 1 is even, then mn + 2m + n + 2 must be ODD Now recognize ...” May 19, 2018 Brent@GMATPrepNow posted a reply to OG12: An arithmetic sequence in the Problem Solving forum “Basically, an arithmetic sequence is a sequence in which each term can be calculated by adding some constant, k, to the preceding term. Some examples: 6, 8, 10, 12, 14,... (adding 2 to each term to get the next term) -1, 6, 13, 20, 27,... (adding 7 to each term to get the next term) 10, 7, ...” May 18, 2018 Brent@GMATPrepNow posted a reply to Jerry travels 8 miles at an average speed of 40 miles per in the Problem Solving forum “Your solution is perfect! That said, another approach is to focus on the 2nd part of the trip. In the first part of the trip, Jerry travels 8 miles at an average speed of 40 miles per hour In the 2nd part of the trip, Jerry stops for 10 minutes, and then travels another 20 miles at an ...” May 18, 2018 Brent@GMATPrepNow posted a reply to m, n and k are positive integers. If the product in the Data Sufficiency forum “Target question: Is k odd? Given: The product mn is odd If the product mn is odd, when we know that m is ODD and n is ODD Statement 1: mn + n + k is odd In other words: (ODD)(ODD) + ODD + k is odd Simplify: ODD + ODD + k is odd Simplify more: EVEN + k is odd This means k must be ...” May 18, 2018 Brent@GMATPrepNow posted a reply to To offset miscellaneous costs, a dealership decides to in the Problem Solving forum “Sorry, vinni.k, but I don''t understand what you are saying. Can you elaborate? Cheers, Brent” May 18, 2018 Brent@GMATPrepNow posted a reply to How many sides does polygon P have? (1) All sides of P have in the Data Sufficiency forum “Target question: How many sides does polygon P have? Statement 1: All sides of P have equal lengths. There are infinitely many polygons that satisfy statement 1. Here are two: Case a: Polygon P is an equilateral triangle. In this case, the answer to the target question is polygon P has 3 ...” May 18, 2018 Brent@GMATPrepNow posted a reply to If a number between 10 and 50 (inclusive) at random. in the Problem Solving forum “I think that listing (while looking for a pattern) and counting is the best/fastest approach here. Let''s list all of the numbers (from 10 to 50 inclusive) such that the tens digit is greater than one digit Numbers with tens digit 1: 10 Numbers with tens digit 2: 20, 21 Numbers with tens ...” May 18, 2018 Brent@GMATPrepNow posted a reply to To offset miscellaneous costs, a dealership decides to in the Problem Solving forum “I''m not entirely sure this question is ambiguous. I read it as: one of the motorcycles (we''ll name it Clark) gets a 7% price increase PLUS an additional increase of$350 These changes are equivalent to a 9% price increase (for Clark) As we can see, it doesn''t make a difference whether each ...”
May 17, 2018
Brent@GMATPrepNow posted a new topic called m and n are positive integers. If mn + 2m + n + 1 is even, in the Problem Solving forum
“m and n are positive integers. If mn + 2m + n + 1 is even, which of the following MUST be true? i) (2n + m)² is even ii) n² + 2n – 11 is even iii) m² – 2mn + n² is odd A) ii only B) ii and iii only C) i and ii only D) i and iii only E) i, ii and iii Answer: E Difficulty ...”
May 17, 2018
Brent@GMATPrepNow posted a reply to Is x < 0? (1) -2x > 0 (2) x^3 < 0 in the Data Sufficiency forum
“Target question: Is x < 0? Statement 1: -2x > 0 Divide both sides by -2 to get: x < 0 So, the answer to the target question is YES, x < 0 Since we can answer the target question with certainty, statement 1 is SUFFICIENT Statement 2: x^3 < 0 Since x^2 must be POSITIVE ...”
May 17, 2018
Brent@GMATPrepNow posted a reply to An investment compounds annually at an interest rate in the Problem Solving forum
“We can use fractions to solve this question. Each year, the investment increases 34.1% This is very close to an increase of 1/3 (33.33%) So, if the investment increases by 1/3 each year, then each year, we can find the value of the investment by multiplying last year''s value by 4/3 (this ...”
May 17, 2018
Brent@GMATPrepNow posted a new topic called m, n and k are positive integers. If the product in the Data Sufficiency forum
“m, n and k are positive integers. If the product mn is odd, is k odd? (1) nm + n + k is odd (2) n² – kn – 6k² is even Answer: D Difficulty level: 600 - 650 Source: www.gmatprepnow.com”
May 16, 2018
Brent@GMATPrepNow posted a reply to basic algebra in the Problem Solving forum
“What is the source of these questions you''ve recently posted? They don''t seem GMAT--worthy. Cheers, Brent”
May 16, 2018
Brent@GMATPrepNow posted a reply to Roger's edge fund is taking x dollars and investing in bonds in the Problem Solving forum
“Roger''s hedge fund is taking x dollars and investing in bonds that yield r percent in simple interest. The amount of interest earned over 2 years is $1000. So, the original investment of x dollars results in$500 interest EACH YEAR In terms of x, what dollar amount invested will yield $4000 ...” May 16, 2018 May 16, 2018 Brent@GMATPrepNow posted a reply to If (-20) + (-19) + (-18) + (-17) + . . . in the Problem Solving forum “First notice that (-20) + (-19) + (-18) + (-17) + . . . + 17 + 18 + 19 + 20 = 0 So, we have: (-20) + (-19) + (-18) + (-17) + . . . + 17 + 18 + 19 + 20 + 21 + 22 + ? + ? + ... + (-2x - 4) = 90 Simplify to get: -0 + 21 + 22 + ? + ? + ... + (-2x - 4) = 90 We can see that we won''t need to add ...” May 16, 2018 Brent@GMATPrepNow posted a reply to when n divided by 3, the remainder is 2. in the Problem Solving forum “IMPORTANT: Many integer property questions can be found quickly by identifying values that satisfy the given information. ---------ASIDE------------------ 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, ...” May 16, 2018 Brent@GMATPrepNow posted a reply to Which of the following numbers is the biggest in the Problem Solving forum “Since we''re dealing with NEGATIVE numbers, the greatest number will be the one with the smallest MAGNITUDE For example, 2 < 3, so we know that -2 is greater than -3 Likewise, 11 < 12, so we know that -11 is greater than -12 Of the values 6/7, 7/8, 9/10, 12/13 and 34/35, the fraction ...” May 16, 2018 Brent@GMATPrepNow posted a reply to Each vote in a certain election went to one of the two candi in the Data Sufficiency forum “We can use the Double Matrix Method here to help us arrange our information. The Double Matrix 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 voters, and the two characteristics are: - male or ...” May 16, 2018 Brent@GMATPrepNow posted a reply to Mark can paint twice as fast as Joe. If Mark starts to paint in the Problem Solving forum “Mark can paint twice as fast as Joe. So, for every 1 foot of wall that Joe paints, Mark can paint 2 feet of wall. In other words, for every 3 feet of wall that the two man paint TOGETHER, Joe moves 1 foot and Mark moves 2 feet. Generally speaking, for every x feet of wall that the two man ...” May 15, 2018 Brent@GMATPrepNow posted a reply to A boat traveled a total of 600 miles in two days. If the in the Problem Solving forum “Let F = number of miles traveled on first day Let S = number of miles traveled on second day A boat traveled a total of 600 miles in two days. So, we can write: F + S = 600 The distance it traveled on the first day was 150 miles less than twice the distance it traveled on the second day ...” May 15, 2018 Brent@GMATPrepNow posted a new topic called If a = 100, what is the value of c? in the Problem Solving forum “https://i.imgur.com/DxjVcg8.png If a = 100, what is the value of c? (1) b = 30 (2) f = 50 Answer: D Source: www.gmatprepnow.com Difficulty level: 500-550” May 15, 2018 Brent@GMATPrepNow posted a new topic called If (-20) + (-19) + (-18) + (-17) + . . . in the Problem Solving forum “If (-20) + (-19) + (-18) + (-17) + . . . + (-2x - 4) = 90, what is the value of x? A) -24 B) -14 C) -10 D) 10 E) 14 Answer: B Source: www.gmatprepnow.com Difficulty level: 550-600” May 15, 2018 Brent@GMATPrepNow posted a reply to ---P---Q---R---S---T--- In the figure above, what is the le in the Data Sufficiency forum “Target question: What is the length of segment PQ? Statement 1: S is the midpoint of segment RT Since we are not given ANY actual measurements (i.e., lengths) whatsoever, there''s no way to determine the length of PQ Statement 1 is NOT SUFFICIENT Statement 2: Segment PT has length 10 and ...” May 15, 2018 Brent@GMATPrepNow posted a reply to w, x, y and z are positive integers. When w is divided by x, in the Data Sufficiency forum “Target question: What is the value of z? Given: w, x, y and z are positive integers. When w is divided by x, the quotient is y, and the remainder is z. Statement 1: x³ - 3x² + 2x = 0 Let''s solve this equation for x. Factor to get: x(x² - 3x + 2) = 0 Factor the quadratic to get: ...” May 15, 2018 Brent@GMATPrepNow posted a reply to Working alone, Manuel finishes cleaning half the house in in the Problem Solving forum “Another option for many work questions is to assign a nice value to the given job. Here, a nice value will be one that works well with the given numbers (6 hours, 1/2 the time, 1/3 of the time) So, have about 36. Let''s say the entire job of cleaning the house consists of cleaning 36 rooms. ...” May 15, 2018 Brent@GMATPrepNow posted a reply to If k is negative, which of the following must also be negati in the Problem Solving forum “NOTE: this is one of those questions that require us to check/test each answer choice. In these situations, always check the answer choices from E to A, because the correct answer is typically closer to the bottom than to the top. For more on this strategy, see my article: ...” May 14, 2018 Brent@GMATPrepNow posted a reply to If 12x + 2y is 80% of 5y, what is the value of x/y ? in the Problem Solving forum “Sionainn''s solution is perfect. It''s the same approach I''d use. However, here''s another approach (for kicks!) Let''s try to find some values for x and y that satisfy the given information: 12x + 2y is 80% of 5y Let''s first let y = 20, and then figure out what value of x is needed. We ...” May 14, 2018 Brent@GMATPrepNow posted a reply to Last year Jenny was 5 feet tall, and this year she is in the Problem Solving forum “Old height: 5 feet = 60 inches New height: 5 feet 6 inches = 66 inches Percent increase = (100)(new - old)/old = (100)(66 - 60)/60 = (100)(6)/60 = 600/60 = 10% Answer: B Cheers, Brent” May 14, 2018 Brent@GMATPrepNow posted a reply to If a = 4b, what percent of 2a is 2b? in the Problem Solving forum “I would have used the same approach that Mitch used. However, here''s an algebraic approach: If a = 4b, then 2a = 8b What percent of 2a is 2b? We can rewrite as: 2b/2a = what percent? Or, we can write: 2b/8b = what percent? Simplify: 1/4 = what percent? Since 1/4 = 25%, the correct ...” May 14, 2018 Brent@GMATPrepNow posted a reply to If x is a positive integer, what is the least common in the Data Sufficiency forum “Another approach: Target question: What is the LCM of x, 6 and 9? ASIDE: The LCM tells us about the prime factors that numbers have in common. For example: The LCM of 20 and 12 is 60 60 = (2)(2)(3)(5). So, the prime factorization of 60 has two 2''s, one 3, and one 5. Now examine the ...” May 14, 2018 Brent@GMATPrepNow posted a reply to If x is a positive integer, what is the least common in the Data Sufficiency forum “Target question: What is the LCM of x, 6 and 9? I''ll show you two different approaches. This first approach uses requires us to be able to think of pairs of values that have given LCM''s. This is a useful skill to have on the GMAT. Statement 1: The least common multiple of x and 6 is 30. ...” May 14, 2018 Brent@GMATPrepNow posted a reply to A car traveled 60 mph from Belnap to Lincoln and 50 mph from in the Problem Solving forum “That''s a perfectly valid approach. Here''s one slight modification: Once we know that the total time = 330/60 + 330/50, we might also see what happens when we find a common denominator BEFORE adding the parts. So, total time = 330/60 + 330/50 = (5)330/300 + (6)(330)/300 = (11)(330)/300 ...” May 14, 2018 Brent@GMATPrepNow posted a reply to Finding the Number of Factors | Short Video in the GMAT Math forum “Good post. Here''s a similar video: https://www.youtube.com/watch?v=lVZ9GXd6ZBE It also covers WHY the formula (for finding the number of factors) works. Cheers, Brent” May 13, 2018 Brent@GMATPrepNow posted a new topic called If 12x + 2y is 80% of 5y, what is the value of x/y ? in the Problem Solving forum “If 12x + 2y is 80% of 5y, what is the value of x/y ? A) 1/6 B) 1/4 C) 2/5 D) 1/2 E) 5/8 Answer: A Source: www.gmatprepnow.com Difficulty level: 550-600” May 13, 2018 Brent@GMATPrepNow posted a new topic called w, x, y and z are positive integers. When w is divided by x, in the Data Sufficiency forum “w, x, y and z are positive integers. When w is divided by x, the quotient is y, and the remainder is z. What is the value of z? 1) x³ - 3x² + 2x = 0 2) The least common multiple of w and x is 30. Answer: A Source: www.gmatprepnow.com Difficulty level: 600-650” May 13, 2018 Brent@GMATPrepNow posted a reply to Is x + y > 6? in the Data Sufficiency forum “Target question: Is x + y > 6? Statement 1: x + 2y > 8 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 = 10. In this case, x + y = 10 + 10 = 20, which is greater than 6. So, the answer to the target question is ...” May 12, 2018 Brent@GMATPrepNow posted a reply to If x > 0, is x^2 < x? in the Data Sufficiency forum “Here''s another approach: Target question: Is x² ＜ x ? This is a good candidate for rephrasing the target question. Aside: Here’s a video with tips on rephrasing the target question: Given: x > 0 Since we''re told that x is POSITIVE, we can safely take x² < x and divide ...” May 12, 2018 Brent@GMATPrepNow posted a reply to If x > 0, is x^2 < x? in the Data Sufficiency forum “Target question: Is x² < x? Statement 1: 0.1 < x < 0.4 A useful property says: If 0 < x < 1, then x² < x Since statement 1 basically tells that 0 < x < 1, we can be certain that x² < x Since we can answer the target question with certainty, statement 1 is ...” May 12, 2018 Brent@GMATPrepNow posted a reply to 3-3*6+2= in the Problem Solving forum “We must follow the order of operations (aka BEDMAS or PEMDAS) Given: 3 - 3 x 6 + 2 Must must perform all divisions and multiplications first. So, 3 - 3 x 6 + 2 = 3 - 18+ 2 Next, when given the options of subtraction and addition, we perform the operations from left to right So, we get: 3 - ...” May 12, 2018 Brent@GMATPrepNow posted a reply to If X and Y are consecutive integers (Y>X), which of the in the Problem Solving forum “If X and Y are consecutive integers, then one number must be EVEN and the other number must be ODD. If one number is ODD and one number is EVEN, then their product must be EVEN So, statement 1 (The product XY is an even number) is ALWAYS TRUE In other words, statement 1 can never be false ...” May 12, 2018 Brent@GMATPrepNow posted a reply to Is x = 3? in the Data Sufficiency forum “What''s the source of this question? On the GMAT, the statements will never contradict each other. In the above question, statement 1 tells us that x definitely equals 3, and statement 2 tells us that x definitely does NOT equal 3 More on this here: ...” May 11, 2018 Brent@GMATPrepNow posted a reply to $\frac{19^2+19}{20}=$ in the Problem Solving forum “Notice that we can factor 19 from the numerator. (19² + 19)/20 = (19)(19 + 1)/20 = (19)(20)/20 = 19 Answer: C Cheers, Brent” May 11, 2018 Brent@GMATPrepNow posted a reply to How many factors does 36^2 have? in the Problem Solving forum “-------ASIDE------------------- If the prime factorization of N = (p^a)(q^b)(r^c) . . . (where p, q, r, etc are different prime numbers), then N has a total of (a+1)(b+1)(c+1)(etc) positive divisors. Example: 14000 = (2^4)(5^3)(7^1) So, the number of positive divisors of 14000 = ...” May 11, 2018 Brent@GMATPrepNow posted a reply to If y + 40x + 2 = 0, what is the in the Data Sufficiency forum “Target question: What is the value of xy? Given: y + 40x + 2 = 0 Rearrange to get: 40x + y = -2 IMPORTANT: We are given one linear equation. If we given a different linear equation, then we can be certain to solve the system of equations for x and y, which means we can determine the value ...” May 11, 2018 Brent@GMATPrepNow posted a reply to The perimeter of a rectangular garden is 80 feet, and the in the Problem Solving forum “Let W = the width of the rectangle Let L = the length of the rectangle The perimeter of a rectangular garden is 80 feet We can write: W + W + L + L = 80 Simplify to get: 2W + 2L = 80 Divide both sides by 2 to get: W + L = 40 The area of the garden is 391 square feet Area = ...” May 11, 2018 Brent@GMATPrepNow posted a reply to A parking lot charges a flat rate of X dollars for any in the Problem Solving forum “2 hours: cost = x dollars 3 hours: cost = x + x/6 dollars 4 hours: cost = x + x/6 + x/6 dollars 5 hours: cost = x + x/6 + x/6 + x/6 dollars 5.25 hours: cost = x + x/6 + x/6 + x/6 + x/6 dollars We must now simplify: x + x/6 + x/6 + x/6 + x/6 dollars Rewrite with common denominator: 6x/6 + ...” May 11, 2018 beatthegmat posted a new topic called Prepping for the GRE When English is Not Your First Language in the GMAT Strategy forum “English is a complex language. Ask around and you’ll hear that even native speakers can find it complicated and sometimes confusing. This can make the GRE® General Test particularly challenging when English is not your first language. With adequate practice, however, you can be sure to feel ...” May 10, 2018 Brent@GMATPrepNow posted a reply to The system of equations above has how many solutions? in the Problem Solving forum “Another approach is to begin solving the system (using the elimination method) and see what happens. Given: x - y = 3 2x = 2y + 6 Take bottom equation and divide both sides by 2 to get: x - y = 3 x = y + 3 Take bottom equation and subtract y from both sides to get: x - y = 3 x - y ...” May 10, 2018 Brent@GMATPrepNow posted a reply to The system of equations above has how many solutions? in the Problem Solving forum “Given: x - y = 3 2x = 2y + 6 Take 2x = 2y + 6 and divide both sides by 2 to get an EQUIVALENT equation x = y + 3 Now subtract y from both sides to get: to get another EQUIVALENT equation x - y = 3 Since this equation (x - y = 3) is identical to the other equation x - y = 3, we can be certain ...” May 10, 2018 Brent@GMATPrepNow posted a reply to Three friends rented a car for a week and divided the cost e in the Problem Solving forum “Let''s start with a word equation: (cost per person with 4 friends) = (cost per person with 3 friends) -$15 Let T = the total cost of renting the car So, cost per person with 4 friends = T/4 And cost per person with 3 friends = T/3 We can now take our word equation and fill in the missing ...”
May 10, 2018
Brent@GMATPrepNow posted a reply to C/D = 9.75 when dividing positive integer C by positive in the Problem Solving forum
“IMPORTANT: There are infinitely many pairs of values of C and D that satisfy the condition that C/D = 9.75 For example, 975/100 = 9.75. In this case, C = 975 and D = 100 Likewise, 195/20 = 9.75. In this case, C = 195 and D = 20 Also, 390/40 = 9.75. In this case, C = 390 and D = 40 And 39/4 = ...”
May 9, 2018
Brent@GMATPrepNow posted a reply to A salesperson for an automobile dealer earns an annual salar in the Problem Solving forum
“Total earnings = (base salary) + (commission) base salary = $25,000 commission = 10% of total sales OVER$100,000 = 10% of (x - $100,000) = 0.1(x -$100,000) So, total earnings = $25,000 + 0.1(x -$100,000) Answer: E Cheers, Brent”
May 9, 2018
Brent@GMATPrepNow posted a reply to When a=x+(1/x) and b=x-(1/x), what is a^2 – b^2? in the Problem Solving forum
“Given: a = x + 1/x and b = x - 1/x Our goal is to find the value of a² - b² To do so, it''s useful to recognize that the expression a² - b² is a difference of squares, which means we can rewrite it. When we do this, we get: a² - b² = (a + b)(a - b) Now replace a and b with their ...”
May 9, 2018
Brent@GMATPrepNow posted a reply to If snow accumulation increased at a constant rate of 30 mill in the Problem Solving forum
“Let''s keep listing EQUIVALENT RATES until we get to 1 millimeter 30 millimeters per hour = 30 millimeters per 60 minutes = 30 millimeters per 3600 SECONDS = 3 millimeters per 360 SECONDS = 1 millimeter per 120 SECONDS Answer: E Cheers, Brent”
May 9, 2018
Brent@GMATPrepNow posted a reply to In the Land of OZ only one or two-letter words are used. in the Problem Solving forum
“6 6 as its units digit ] Likewise 65² = (65)(65) = ----5 So, we get: The number of words lost = 6 + ---6] - 5 + ----5] = (------2) - (----0) = ------2 Since only answer choice E has a units digit of 2, the correct answer must be E Cheers, Brent”
May 8, 2018
Brent@GMATPrepNow posted a reply to If a,b,x, and y are positive integers, is a^-x > b^-y? ( in the Data Sufficiency forum
“Target question: Is a^(-x) > b^(-y)? This is a great candidate for rephrasing the target question. Aside: Here’s a video with tips on rephrasing the target question: First recognize the following: a^(-x) = 1/(a^x) and b^(-y) = 1/(b^y) So, we can ask Is 1/(a^x) > 1/(b^y)? Also, ...”
May 8, 2018
Brent@GMATPrepNow posted a reply to Two integers will be randomly selected from sets A and B, in the Problem Solving forum
“Take the task of creating products and break it into stages. Stage 1: Select a number from set A There are 5 numbers to choose from, so we can complete stage 1 in 5 ways Stage 2: Select a number from set B There are 4 numbers to choose from, so we can complete stage 2 in 4 ways By the ...”
May 8, 2018
Brent@GMATPrepNow posted a reply to For an integer n greater than 1, n* denotes the product of in the Problem Solving forum
“7* = 7! = (7)(6)(5)(4)(3)(2)(1) So, 7* + 2 = (7)(6)(5)(4)(3)(2)(1) + 2 = 22 So, 7* + 2 is NOT a prime number 7* + 3 = (7)(6)(5)(4)(3)(2)(1) + 3 = 33 So, 7* + 3 is NOT a prime number 7* + 4 = (7)(6)(5)(4)(3)(2)(1) + 4 = 44 So, 7* + 4 is NOT a prime number . . . . 7* + 7 = ...”
May 8, 2018
beatthegmat posted a reply to Delete account? in the Suggestions and Feedback forum
“Hi fsb_20 Your account has been deleted.”
May 7, 2018
Brent@GMATPrepNow posted a reply to Is x > y? in the Data Sufficiency forum
“Target question: Is x > y? Statement 1: 6x > 5y 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 = -1. Notice that 6x > 5y becomes 6 > -5, which is true. In this ...”
May 7, 2018
Brent@GMATPrepNow posted a reply to If 5m=25^{2n}, what is the value of m, in terms of n? in the Problem Solving forum
“Given: 5m = 25^(2n) Rewrite 25 as 5² to get: 5m = (5²)^(2n) Apply power of a power law to get: 5m = 5^(4n) Divide both sides by 5 to get: m = [5^(4n)]/5 Since 5 = 5¹, we get: : m = [5^(4n)]/(5¹) Apply quotient law to get: m = 5^(4n - 1) Answer: C Cheers, Brent”
May 7, 2018
Brent@GMATPrepNow posted a reply to Is y = 7? in the Data Sufficiency forum
“Target question: Is y = 7? Statement 1: x - 4 = 0 In other words, x = 4 Since we have no information about y, statement 1 is NOT SUFFICIENT Statement 2: (x - 3)(y - 7) = 0 This tells us that EITHER x = 3 OR y = 7 So, y COULD equal 7, or y might not equal 7 For example, consider ...”
May 6, 2018
Brent@GMATPrepNow posted a reply to W, X, Y and Z each represent a different number in the Problem Solving forum
“I believe Mitch has provided the best/fastest approach. Cheers, Brent”
May 6, 2018
Brent@GMATPrepNow posted a reply to If a car went the first third of the distance at 80 kmh in the Problem Solving forum
“Here''s an algebraic approach: Let d = 1/3 of the total distance traveled So, the car traveled d km at 80 kmh, then the car traveled d km at 24 kmh, and then d km at 48 kmh Average speed = (total distance traveled)/(total travel time) Total distance traveled = d + d + d = 3d time = ...”
May 6, 2018
Brent@GMATPrepNow posted a reply to Sheila works 8 hours per day on Monday, Wednesday and Friday in the Problem Solving forum
“We can avoid long division if we make an important observation. Let''s take it from the point were you got: earning per hour = $324/36 You might notice that$360/36 = $10 Also notice that$324 = $360 -$36 So, $324/36 = ($360 - $36)/36 =$360/36 - $36/36 = 10 - 1 = 9 = Answer choice C ...” May 6, 2018 Brent@GMATPrepNow posted a reply to In a certain school, the ratio of boys to girls is in the Problem Solving forum “Another approach: Let B = # of boys Let G = # of girls The ratio of boys to girls is 5 to 13. We can write: B/G = 5/13 Cross multiply to get: 13B = 5G There are 72 more girls than boys We can write G = B + 72 Alternatively, we can write: G - 72 = B We now have two equations: 13B = ...” May 6, 2018 Brent@GMATPrepNow posted a reply to In a certain school, the ratio of boys to girls is in the Problem Solving forum “One approach: GIVEN: the ratio of boys to girls is 5 to 13 There are several possible cases that meet this condition: - there are 5 boys and 13 girls - there are 10 boys and 26 girls - there are 15 boys and 39 girls . . . NOTE: We''re also told that there are 72 more girls than ...” May 6, 2018 Brent@GMATPrepNow posted a reply to If$936 are divided bettween worker A and B in the ratio in the Problem Solving forum
“Your solution is perfect. I''d just like to point out how get convert 7/12 to a percent. As you''ve shown, to convert a fraction to a percent, we convert to a decimal and multiply it by 100 So, (7/12)(100) = 700/12 = 350/6 = 175/3 = 58 1/3 = 58 + 0.333333.... = 58.333333....% As you ...”
May 5, 2018
Brent@GMATPrepNow posted a reply to A discount of 20 percent on an order of goods in the Problem Solving forum
“Let''s start with a nice number Let $100 be the ORIGINAL price. So, a 20% discount on$100 = $20, which means the discounted price =$100 - $20 =$80 Next, a 20% discount on $80 =$16, which means the NEW discounted price = $80-$16 = $64 So, if the ORIGINAL price =$100, the DOUBLE ...”
May 4, 2018
Brent@GMATPrepNow posted a reply to In a room filled with 7 people, 4 people phave exactly 1 in the Problem Solving forum
“First we need to recognize that the given information tells us that the 7 people consist of: - a sibling trio - a sibling pair - and another sibling pair Using counting techniques: For this question, it''s easier to find the complement. So P(not siblings) = 1 - P(they are siblings) ...”
May 4, 2018
Brent@GMATPrepNow posted a reply to If c and f are integers, is zc > zf? in the Data Sufficiency forum
“Target question: Is zc > zf? Statement 1: z³c > z³f This tells us that z ≠ 0 It also means that z² > 0 Since z² is POSITIVE, we can safely divide both sides of the statement 2 inequality by z² to get: xc > zf PERFECT!! The answer to the target question is YES, xc IS ...”
May 4, 2018
Brent@GMATPrepNow posted a reply to If x and y are positive integers and x>y, is x/y an integ in the Data Sufficiency forum
“Target question: Is x/y an integer? Given: x and y are positive integers and x>y Statement 1: x is a multiple of 10 No information about y. Statement 1 is NOT SUFFICIENT Statement 2: y is a multiple of 2 No information about x. Statement 2 is NOT SUFFICIENT Statements 1 ...”
May 4, 2018
Brent@GMATPrepNow posted a reply to If x is the sum of the first 10 positive multiples of 3 and in the Problem Solving forum
“x is the sum of the first 10 positive multiples of 3 So, x = 3 + 6 + 9 + 12 + .... Factor out the 3 to get: x = 3(1 + 2 + 3 + 4 + . . . . + 9 + 10) y is the sum of the first 10 positive multiples of 2 So, y = 2 + 4 +6 + 8 + 10 + ... Factor out the 2 to get: y = 2(1 + 2 + 3 + 4 + . . . . + 9 + ...”
May 4, 2018
Brent@GMATPrepNow posted a reply to Five percent of a certain grass seed is timothy. If the in the Problem Solving forum
“We have 240 pounds of the seed mixture, and 5% of the mixture is timothy. So: TOTAL weight of timothy = 5% of 240 pounds = 12 pounds So, we there are 12 pounds of timothy in the mixture, and 2 pounds of timothy is needed for 1 acre This means 4 pounds of timothy is needed for 2 acres And 6 ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to Some fourth graders are choosing foursquare teams at in the Problem Solving forum
“This is a somewhat ambiguous question since it''s hard to tell whether each team member''s position matters. For example, if the question were rephrased to ask how many 9-person baseball teams can be created from 9 people, we might say the correct answer is 1. However, if we consider the ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to What is the largest integer if the sum of three consecutive in the Problem Solving forum
“Let x = the smallest value So, x + 2 = the middle value And x + 4 = the biggest value The sum is 318 So, we can write x + (x+2) + (x+4) = 318 Simplify: 3x + 6 = 318 Subtract 6 from both sides to get: 3x = 312 Solve: x = 104 So, the SMALLEST value = 104 This means 106 is the MIDDLE value ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to What is the units digit of 36^y? (A) y is a positive in the Data Sufficiency forum
“Target question: What is the units digit of 36^y? Statement 1: y is a positive integer So, y = 1 or 2 or 3 or 4 or 5 or... Notice that 36^1 = 36 (units digit = 6) Notice that 36^2 = ---6 (units digit = 6) Notice that 36^3 = ---6 (units digit = 6) Notice that 36^4 = ---6 (units digit = 6) ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to A group of 8 friends want to play doubles tennis. in the Problem Solving forum
“Let the 8 people be: A, B, C, D, E, F, G, and H Take the task of creating the teams and break it into stages. Stage 1: Select a partner for person A There are 7 people to choose from, so we can complete stage 1 in 7 ways ASIDE: There are now 6 people remaining. Each time we pair up two ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to George tried to compute the mean average of his 8 test in the Problem Solving forum
“Let T = the sum of all of George''s test scores. George divided the sum of his test scores by 7 to get 96. So we get: T/7 = 96 Multiply both sides by 7 to get: T = (96)(7) To get the ACTUAL average, George SHOULD have divided the sum of his test scores by 8 So, ACTUAL average = T/8 = ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to For all positive integers m and n, the expression m X n in the Problem Solving forum
“19∆9 = the remainder when (19+9) is divided by (19-9) = the remainder when 28 is divided by 10 = 8 So, (19∆9)∆2 = 8∆2 = the remainder when (8+2) is divided by (8-2) = the remainder when 10 is divided by 6 = 4 ------------------------------------------------------------- 9∆2 = the ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to If x is a positive integer, is x/30 a terminating decimal? in the Data Sufficiency forum
“Target question: Is x/30 a terminating decimal? This is a good candidate for rephrasing the target question. -------------ASIDE------------------ Let''s say that x = a/b where the fraction a/b is written in simplest terms. There''s a nice rule that says something like, If a/b results in a ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to How many odd three-digit integers greater than 800 are there in the Problem Solving forum
“Here''s a similar one to practice with: http://www.beatthegmat.com/counting-a-3-digit-number-greater-than-700-t288550.html Cheers, Brent”
May 3, 2018
Brent@GMATPrepNow posted a reply to How many multiples of 4 lie between 4^4 and 4^5, inclusive? in the Problem Solving forum
“Mitch used the same approach I would have used, so here''s a different solution. 4^4 = (4³)(4) = (64)(4) 4^5 = (4⁴)(4) = (256)(4) So, we want the multiples of 4 from (64)(4) to (256)(4) inclusive. The multiples of 4 are: (64)(4), (65)(4), (66)(4), (67)(4), (68)(4), . . . (256)(4) A ...”
May 3, 2018
Brent@GMATPrepNow posted a reply to If 25(5^x) = 1 then x= in the Problem Solving forum
“Given: (25)(5^x) = 1 Divide both sides by 25 to get: 5^x = 1/25 (aka 1/5²) Rewrite 1/25 as 5^(-2) to get: 5^x = 5^(-2) So, x = -2 Answer: A Cheers, Brent”
May 2, 2018
Brent@GMATPrepNow posted a reply to The distance between Alice’s house and Bob's is 120 miles. in the Problem Solving forum
“The correct answer is showing up as B Upon re-reading the question, we can see that it''s somewhat ambiguous, because it doesn''t specify where Alice and Bob are when they begin their journeys (although I also assumed that Alice started at her own house and Bob started at his own house). If each ...”
May 2, 2018
Brent@GMATPrepNow posted a reply to Larry can build a model car in 3 hours, Moe can build the in the Problem Solving forum
“Your approach (of assigning a nice value to the job) is perfect. Here''s another approach.... RULE: If a person can complete an entire job in k hours, then in ONE HOUR, the person can complete 1/k of the job Example: If it takes Sue 5 hours to complete a job, then in ONE HOUR, she can complete ...”
May 2, 2018
Brent@GMATPrepNow posted a reply to is p prime number in the Data Sufficiency forum
“Target question: Is p a prime number? Given: p is an integer greater than 1 Statement 1: p is a factor of 13 The only positive factors of 13 are 1 and 13 Since we''re told that p is greater than 1, we can conclude that p MUST equal 13 So, the answer to the target question is YES, p IS ...”
May 2, 2018
Brent@GMATPrepNow posted a reply to If x and y are positive integers, what is the remainder when in the Data Sufficiency forum
“Target question: What is the remainder when x+y is divided by 2? Statement 1: xy is divisible by 4 Let''s TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 2 and y = 4. Here xy = (2)(4) = 8, and 8 is divisible by 4. In this case, x +y ...”
May 2, 2018
Brent@GMATPrepNow posted a reply to When a positive integer n is divided by 29, what is the in the Data Sufficiency forum
“Target question: What is the remainder when n is divided by 29? Statement 1: n-5 is divisible by 29 So, we can say that: n-5 = 29k for some integer k Add 5 to both sides of the equation to get: n = 29k + 5 We can see that n is 5 greater than some multiple of 29 So, if we divide n by 29, ...”
May 1, 2018
Brent@GMATPrepNow posted a reply to In the figure below, the area of triangle PQR is 40. in the Problem Solving forum
“We can see that: (area of ∆PQS) + (area of ∆QRS) = (area of ∆PQR) So, we can write: (area of ∆PQS) + (area of ∆QRS) = 40 We also have enough information to determine the area of ∆PQS Area of triangle = (base)(height)/2 So, area of ∆PQS = (5)(6)/2 = 30/2 = 15 Now add this ...”
May 1, 2018
Brent@GMATPrepNow posted a reply to Four values from a data set of 5 elements are 10, 10, 11, an in the Data Sufficiency forum
“Let''s say that x = the missing data value Target question: What is the value of x? Given: The other 4 values are 10, 10, 11 and 11 Statement 1: The range of the data set is 2 So, (the biggest value) - (the smallest value) = 2 The problem here is that x COULD be the smallest value, ...”
May 1, 2018
Brent@GMATPrepNow posted a reply to Working alone at its constant rate, machine A can complete a in the Problem Solving forum
“Working alone at its constant rate, machine A can complete a job in 24 hours. The work rate of machine B is 1/2 that of machine A. So, it must take Machine B 48 hours to complete the job. Now let''s assign a nice value to the job. That is, we''ll assign a value that works well with 24 hours ...”
May 1, 2018
Brent@GMATPrepNow posted a reply to A rectangular wall is completely filled with square tiles of in the Problem Solving forum
“. . . and no tiles with a common side are the same color To meet this condition, it MUST be the case that the yellow and orange squares are arranged in a checkerboard pattern. In such a checkerboard pattern, the colors alternate yellow, orange, yellow, orange, yellow, orange etc This means half ...”
April 30, 2018
Brent@GMATPrepNow posted a reply to In an electric circuit, two resistors with resistances x and in the Problem Solving forum
“The reciprocal of r is equal to the sum of the reciprocals of x and y So, 1/r = 1/x + 1/y We must solve this equation for r. Take: 1/r = 1/x + 1/y Rewrite the right side with a COMMON DENOMINATOR of xy: 1/r = y/xy + x/xy Combine the two terms to get: 1/r = (y + x)/xy Since we have two ...”
April 30, 2018
Brent@GMATPrepNow posted a reply to The minimum of the integers x, y, and z is 10 and their aver in the Problem Solving forum
“Key concept: If we know the sum of a set of numbers, and we want to MAXIMIZE the biggest number in the set, we must MINIMIZE all of the other numbers. GIVEN: Average of x, y, and z is 11 So, (x + y + z)/3 = 33 This means x + y + z = 33 Great! We know the sum of the values. In order to ...”
April 30, 2018
Brent@GMATPrepNow posted a reply to During one day, a door-to-door salesman sold three fourths in the Problem Solving forum
“If 3/4 of the bricks were SOLD, then the remaining bricks (1/4 of the bricks) were NOT SOLD. If 150 = 1/4 of the bricks, then 450 = 3/4 of the bricks In other words, the salesman sold 450 bricks If 450 bricks were sold at $0.25, then the money collected = (450)($0.25) = $112.50 Answer: D ...” April 30, 2018 Brent@GMATPrepNow posted a reply to If the profit on a product is 20 percent of its sales price, in the Problem Solving forum “Choosing numbers that satisfy the given conditions (as others above have done) is the best/fastest approach. Here''s a (longer) algebraic approach. Let SALE price = x So, PROFIT = 20% of x = 0.2x COST PRICE = SALE PRICE - PROFIT = x - 0.2x = 0.8x What percent is the profit of the ...” April 30, 2018 Brent@GMATPrepNow posted a reply to Double matrix method in the Data Sufficiency forum “This question type (overlapping sets) is VERY COMMON on the GMAT, so be sure to master the Double Matrix Method. Here''s a video covering the strategy: Easy Problem Solving questions - https://www.beatthegmat.com/finance-majors-non-finance-majors-overlapping-set-question-t167425.html Medium ...” April 30, 2018 Brent@GMATPrepNow posted a reply to Mud from a lake on an uninhabited wooded island in the Critical Reasoning forum “PREMISE: Island lake contains toxic chemicals PREMISE: The chemicals were not dumped in the lake, and water from Lake Superior cannot reach the lake We want to find the most reasonable conclusion that follows from this information (A) The waters of the island lake are more severely polluted ...” April 30, 2018 Brent@GMATPrepNow posted a reply to If a certain dog ate 1/5 of his food on a certain day in the Problem Solving forum “Your approach is great. Another approach would be to choose some numbers that satisfy the given conditions. . . . a certain dog ate 1/5 of his food on a certain day So, let''s say the dog had 5 pounds of food available. If the dog ate 1/5 of its food, then it ate 1/5 of 5 pounds. So, the ...” April 29, 2018 Brent@GMATPrepNow posted a reply to Is positive integer z greater than 275? in the Data Sufficiency forum “Target question: Is positive integer z greater than 275? Statement 1: z is a multiple of 21 Let''s TEST some values. There are several values of z that satisfy statement 1. Here are two: Case a: z = 21, in which case, the answer to the target question is NO, z is NOT greater than 275 ...” April 28, 2018 Brent@GMATPrepNow posted a reply to $If \, 8^{13}=2^z , then \, z=$ in the Problem Solving forum “GIVEN: 8^13 = 2^z We want to rewrite our powers so that they have the SAME BASE Rewrite 8 as 2^3 to get: ( 2^3)^13 = 2^z Simplify left side to get: 2^39 = 2^z So, it must be the case that 39 = z Answer: E Cheers, Brent” April 27, 2018 Brent@GMATPrepNow posted a reply to If x is a positive integer greater than 1, is 1/x in the Data Sufficiency forum “Target question: Is 1/x a terminating decimal? This is a good candidate for rephrasing the target question. There''s a nice rule that says something like, If a/b results in a terminating decimal, then the denominator, b, MUST be the product of 2''s and 5''s only! So, for example, if b = 20, ...” April 27, 2018 Brent@GMATPrepNow posted a reply to If the average of 2x and 4x is 12, then x in the Problem Solving forum “Given: the average of 2x and 4x is 12 We can write: (2x + 4x)/2 = 12 Simplify: 6x/2 = 12 Simplify: 3x = 12 Solve: x = 4 Answer: D Cheers, Brent” April 27, 2018 Brent@GMATPrepNow posted a reply to 1/2 of 0.2 percent equals in the Problem Solving forum “Fraction, decimals and percents are all similar ways of expressing a quantity. For example: 19% = 19/100 = 0.19 123% = 123/100 = 1.23 2% = 2/100 = 0.02 So, 0.2% = 0.2/100 = 2/1000 = 0.002 So, 1/2 of 0.2 percent = 1/2 of 0.002 = 0.0001 Answer: D Cheers, Brent” April 27, 2018 Brent@GMATPrepNow posted a reply to Is b an even integer? in the Data Sufficiency forum “Target question: Is b an even integer? Statement 1: The product of b and integer c is even. Let''s TEST some values. There are several values of b and c that satisfy statement 1. Here are two: Case a: b = 2 and c = 3. Here, the product bc = (2)(3) = 6, which is even. In this case, b = 2, ...” April 27, 2018 Brent@GMATPrepNow posted a reply to What is the perimeter of a regular polygon with in the Problem Solving forum “Sum of ALL sides in an n-sided polygon = (n - 2)(180) degrees So, EACH ANGLE in a regular n-sided polygon = (n - 2)(180)/n degrees We''re told that EACH ANGLE is 144°, so we can write: (n - 2)(180)/n = 144 Multiply both sides by n to get: (n - 2)(180) = 144n Expand left side: 180n - 360 = ...” April 27, 2018 Brent@GMATPrepNow posted a reply to Is median of a, b and c equal to their average (arithmetic m in the Data Sufficiency forum “Target question: Is the median of a, b and c equal to their average (arithmetic mean)? Statement 1: a ≤ b ≤ c Let'' TEST some values. There are several values of a, b and C that satisfy statement 1. Here are two: Case a: a = 1, b = 1 and c = 1. The median = 1 = mean. In this case, the ...” April 26, 2018 Brent@GMATPrepNow posted a reply to ACME’s manufacturing costs for sets of horseshoes include in the Problem Solving forum “That''s a great solution. Here''s a slight twist: It COSTS$19.75 per set, and each set is SOLD for $52.50 So, the company makes approximately$33 per set ($52.50 -$19.75 ≈ $33) The company sold 987 sets. So, the profit ≈ ($33)(1000) ≈$33,000 Keep in mind, that there''s also ...” April 26, 2018 Brent@GMATPrepNow posted a reply to A certain box has 10 cards written integers from 1 to 10 in the Problem Solving forum “As AAPL has shown, the average value of the ten cards is 5.5 So, we want to find P(sum of 2 cards is less than 5.5) We can use combinations to determine the umber of ways to select 2 of the 10 cards We can select 2 cards from 10 cards is 10C2 ways (= 45 ways) When we examine the answer ...” April 25, 2018 Brent@GMATPrepNow posted a reply to What is the median of m, n and 5? in the Data Sufficiency forum “Target question: What is the median of m, n and 5? Statement 1: m + n = 10 Let''s examine the ONLY TWO possible cases: m and n are equal and m and n are NOT equal Case a: m and n are equal. That is m = 5 and n = 5. In this case, the set = {5, 5, 5 }, in which case the answer to the target ...” April 25, 2018 beatthegmat posted a new topic called 5 Terror-inducing, Success-busting, Career-ending Mistakes in the MBA Student Life forum “Nobody is perfect. Bill Gates ignored the signs showing the importance of internet search. Richard Branson believed he could oust Coca-Cola and Pepsi with his meager Virgin Cola. Tim Cook launched Apple Maps before it was ready. Everyone makes mistakes, even those people who are largely regarded as ...” April 24, 2018 Brent@GMATPrepNow posted a reply to The population of City X doubles every 25 years in the Problem Solving forum “Let''s make a table TIME | POPULATION Now: 20,000 25 years from now: 40,000 50 years from now: 80,000 75 years from now: 160,000 100 years from now: 320,000 125 years from now: 640,000 150 years from now: 1,280,000 So, it will take 150 years (aka 1.5 centuries) for the population to ...” April 24, 2018 Brent@GMATPrepNow posted a reply to helpp!! with trianglee in the Data Sufficiency forum “Given: In triangle ABC, point X is the midpoint of side AC and point Y is the midpoint of side BC. If point R is the midpoint of line segment XC and if point S is the midpoint of line segment YC Let''s make a few observations before we do anything else. As others have pointed out before me, the ...” April 24, 2018 Brent@GMATPrepNow posted a reply to QR-162 in the Problem Solving forum “Since OC = AC, ∆AOC is an isosceles triangle, which means ∠OAC is also x° https://s1.postimg.cc/568w34movv/image.png Since all 3 angles in ∆AOC must add to 180°, we can conclude that ∠OCA = (180-2x)° https://s1.postimg.cc/27wlzmeuu3/image.png Since angles on a LINE must add to ...” April 24, 2018 Brent@GMATPrepNow posted a reply to Alice and Bruce each bought a refrigerator, and the sum of in the Problem Solving forum “We can also solve the question algebraically, using 1 variable or 2 variables. Here''s a solution with 1 variable: Given: Twice of what Alice paid was$75 more than what Bruce paid Let x = the amount Alice paid So, 2x - 75 = the amount Bruce paid Given: The sum of their purchases was ...”
April 24, 2018
Brent@GMATPrepNow posted a reply to Alice and Bruce each bought a refrigerator, and the sum of in the Problem Solving forum
“This question lends itself nicely to testing the answer choices We''ll start with answer choice C ($425), the middle value. If Alice paid$425, how much did Bruce pay? Given: twice of what Alice paid was $75 more than what Bruce paid Two times$425 = $850, so Bruce paid$775 (since $850 - ...” April 24, 2018 Brent@GMATPrepNow posted a reply to Set T consists of 82 consecutive odd integers. If the sum of in the Problem Solving forum “Here''s another approach: There''s a nice rule that says, "In a set where the numbers are equally spaced, the mean will equal the median." For example, in each of the following sets, the mean and median are equal: {7, 9, 11, 13, 15} {-1, 4, 9, 14} {3, 4, 5, 6} Since set T ...” April 24, 2018 Brent@GMATPrepNow posted a reply to Is a^5 divisible by 4? in the Data Sufficiency forum “Target question: Is a^5 divisible by 4? Statement 1: a^5 – 8 is divisible by 4. In other words, a^5 – 8 is a MULTIPLE OF 4 So, we can say that: a^5 – 8 = 4k for some integer k Add 8 to both sides to get: a^5 = 4k + 8 (for some integer k) Factor the right side: a^5 = 4(k + 2) (for ...” April 24, 2018 Brent@GMATPrepNow posted a reply to P persons have decided to rent a van to tour while on in the Problem Solving forum “P persons have decided to rent a van to tour while on holidays. The price of the van is x dollars and each person is to pay an equal share. ORIGINAL cost per person = (total cost)/(number of people paying) = x/P D persons cancel their trip thus failing to pay their share So, now the number of ...” April 24, 2018 Brent@GMATPrepNow posted a reply to How many possible 7-digit codes can be formed from the lette in the Problem Solving forum “When we want to arrange a group of items in which some of the items are identical, we can use something called the MISSISSIPPI rule. It goes like this: If there are n objects where A of them are alike, another B of them are alike, another C of them are alike, and so on, then the total number of ...” April 24, 2018 Brent@GMATPrepNow posted a reply to How many 5 digit numbers have at least o in the Problem Solving forum “NOTE: We can solve this question without performing lengthy calculations (e.g., 9^5) # of 5-digit numbers with at least one zero digit = (TOTAL number of 5-digit numbers) - (number of 5-digit numbers without ANY 0''s) As Keith shows us above, we get: # of 5-digit numbers with at least one ...” April 23, 2018 Brent@GMATPrepNow posted a reply to Set T consists of 100 consecutive odd integers. If k is an i in the Problem Solving forum “One more approach: If Set T COULD look like this: { -99, -97 ..... -3, -1, 1, 3......97, 99 }, in which case the median = zero We can see that answer choices A, B, D and E could equal zero, so we can ELIMINATE them. Here''s what I mean: A) k² - k - 6 = (k + 2)(k - 3). So, answer choice ...” April 23, 2018 Brent@GMATPrepNow posted a reply to If 3 < x < 7, Which of the following must be true? in the Problem Solving forum “If x > 3, then x COULD equal 3.00000000000000000000000001, in which case x^2 will be less than 9.0001 This means we can ELIMINATE answer choices A, B, C and E By the process of elimination, we''re left with D Cheers, Brent” April 23, 2018 Brent@GMATPrepNow posted a reply to Is the product of x and y a prime number? in the Data Sufficiency forum “Target question: Is the product xy a prime number? Statement 1: x² = 1 This tells us that either x = 1 or x = -1, but it provides NO INFORMATION about y. Consider these two possible cases: Case a: x = 1 and y = 3. In this case, xy = (1)(3) = 3, which is prime. So, the answer to the ...” April 23, 2018 Brent@GMATPrepNow posted a reply to Is s = r? in the Data Sufficiency forum “Target question: Is s = r ? Statement 1: s² = r² This statement doesn''t FEEL sufficient, so I''ll TEST some values. There are several values of r and s that satisfy statement 1. Here are two: Case a: r = 1 and s = 1. Notice that s² = r² becomes (1)² = (1)², which satisfies the ...” April 23, 2018 Brent@GMATPrepNow posted a reply to If n is an integer, is n - 1 even? in the Data Sufficiency forum “Some important rules: 1. ODD +/- ODD = EVEN 2. ODD +/- EVEN = ODD 3. EVEN +/- ODD = ODD 4. EVEN +/- EVEN = EVEN Target question: Is n - 1 even? Statement 1: n - 2 is odd In other words, we can write n - 2 = ODD Add 1 to both sides to get: n - 2 + 1 = ODD + 1 Simplify: n - 1 = ODD + ...” April 23, 2018 Brent@GMATPrepNow posted a reply to If x^2=x+1, then x^3=? in the Problem Solving forum “GIVEN: x² = x + 1 We want to determine the value of x³ So, let''s take the given equation and multiply both sides by x to get: (x)(x²) = (x)(x + 1) Simplify: x³ = x² + x Check the answer choices. . . . . x² + x is not there! At this points, we need to use the given information to ...” April 23, 2018 Brent@GMATPrepNow posted a reply to Three cannons are firing at a target. in the Problem Solving forum “P[all shots hit target] is not the complement of P[no shots hit target] If what is the opposite of "none of the shots hit the target"? Well, it''s can be 1 shot hits target or 2 shots hit target or all 3 shots hit target. So, if we''re going to use the complement here, we must ...” April 22, 2018 Brent@GMATPrepNow posted a reply to Three cannons are firing at a target. in the Problem Solving forum “P(1st MISSES target) = 1 - P(1st HITS target) = 1 - 0.3 = 0.7 P(2nd MISSES target) = 1 - P(2nd HITS target) = 1 - 0.4 = 0.6 P(3rd MISSES target) = 1 - P(3rd HITS target) = 1 - 0.5 = 0.5 ---------------------------- P(none hit the target) = P(1st misses target AND 2nd misses target AND 3rd ...” April 22, 2018 Brent@GMATPrepNow posted a new topic called Set T consists of 82 consecutive odd integers. If the sum of in the Problem Solving forum “Set T consists of 82 consecutive odd integers. If the sum of the integers is 3⁸ - 165, what is the median of set T? A) 78 B) 80 C) 82 D) 84 E) 86 Answer: A Source: www.gmatprepnow.com Estimated difficulty level: 650-700 Cheers, Brent” April 21, 2018 Brent@GMATPrepNow posted a new topic called Set T consists of 100 consecutive odd integers. If k is an i in the Problem Solving forum “Set T consists of 100 consecutive odd integers. If k is an integer, which of the following CANNOT equal the median of set T? A) k² - k - 6 B) k² + 8k + 15 C) 4k² + 4k + 1 D) k³ - 4k² - k E) 3k³ - 27k² Answer: C Source: www.gmatprepnow.com Estimated difficulty level: 650-700 ...” April 21, 2018 Brent@GMATPrepNow posted a reply to A toy store regularly sells all stock at a discount of in the Problem Solving forum “Your solution is great, but you can save some time by using the fact that the answer choices are spread out nicely. To get the LOWEST possible price (after the two discounts), we must apply the biggest discount (which is a 40% discount) So, AFTER the 40% discount, customers will pay 60% of ...” April 20, 2018 Brent@GMATPrepNow posted a reply to The "prime sum" of an integer n greater than 1 is in the Problem Solving forum “This question requires us to find the prime factorization of the answer choices A. 440 = (2)(2)(2)(5)(11). PRIME SUM = 2 + 2 + 2 + 5 + 11 = 22 B. 512 = (2)(2)(2)(2)(2)(2)(2)(2)(2) PRIME SUM = 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 18 C. 620 = (2)(2)(5)(31) PRIME SUM = 2 + 2 + 5 + 31 = 40 ...” April 20, 2018 Brent@GMATPrepNow posted a reply to If x and y are integers, is x+y an even in the Data Sufficiency forum “Target question: Is x+y an even integer? Statement 1: x+3y is even There are 4 possible cases to consider. Let''s test them all Case a: x is ODD and y is ODD. Notice that x +3y = ODD + (3)(ODD) = ODD + ODD = EVEN. In this case, x + y = ODD + ODD = EVEN. So, the answer to the target ...” April 20, 2018 Brent@GMATPrepNow posted a reply to If the sum of the squares of two positive integers is 106, w in the Problem Solving forum “Your solution is perfect. I can''t think of a different approach. Cheers, Brent” April 20, 2018 Brent@GMATPrepNow posted a reply to If -3x < 6, which of the following must be true? in the Problem Solving forum “Given: -3x < 6 Divide both sides by -3 to get: x > -2 Answer: D Cheers, Brent” April 20, 2018 Brent@GMATPrepNow posted a reply to if A = P^Q what is the value of A if in the Problem Solving forum “Given: A = P^Q Given: P = -1 Take A = P^Q and replace P with -1 to get: A = (-1 )^Q So, the value of A depends on the value of Q. Let''s test some different values of Q. If Q = 1, then A = (-1 )^1 = -1 If Q = 2, then A = (-1 )^2 = (-1)(-1) = 1 Since we can have two different values ...” April 20, 2018 Brent@GMATPrepNow posted a reply to A certain restaurant offers 8 different salads in the Problem Solving forum “Take the task of creating a meal and break it into stages. Stage 1: Select 1 salad There are 8 different salads from which to choose, so we can complete stage 1 in 8 ways Stage 2: Select 1 main course There are 5 different main courses from which to choose, so we can complete stage 2 in ...” April 20, 2018 Brent@GMATPrepNow posted a reply to If 8^x = 2^12, what is x? in the Problem Solving forum “We need to rewrite the powers with the SAME BASES. In this case, we can rewrite them with a common base of 2 Given: If 8^x = 2^12, what is x? Rewrite 8 as 2³ to get: (2³)^x = 2^12 Apply Power of a Power rule to get: 2^(2x) = 2^12 So, we can conclude that: 2x =12 Solve: x = 6 Answer: ...” April 20, 2018 Brent@GMATPrepNow posted a reply to What is the value of y? in the Data Sufficiency forum “Target question: What is the value of y? Statement 1: y² + 8y + 16 = 0 Factor to get: (y + 4)(y + 4) = 0 So, y MUST equal -4 Since we can answer the target question with certainty, statement 1 is SUFFICIENT Statement 2: y < 0 If y is NEGATIVE, then there are infinitely many ...” April 20, 2018 Brent@GMATPrepNow posted a reply to 200 is what percent of 40? in the Problem Solving forum “40 is 100% of 40 So, 500 must be MORE THAN 100% of 40 We can eliminate A, B, C, and D Answer: E Cheers, Brent” April 20, 2018 Brent@GMATPrepNow posted a reply to GMATPrep Practice Exam Problem 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”
April 19, 2018
Brent@GMATPrepNow posted a reply to Which of the following must be equal to 300% in the Problem Solving forum
“p % = p/100 So, for example, 19% = 19/100 and 245% = 245/100 So, 300% of the value of x = 300/100 of x = (300/100)(x) = 3x = D Cheers, Brent”
April 19, 2018
Brent@GMATPrepNow posted a reply to What was the percent increase in the value of a certain in the Data Sufficiency forum
“Target question: What was the percent increase in the value of a certain antique from January 1, 1981, to December 31, 1981? Percent increase = 100(new - old)/old So, we can answer the target question if we have the OLD value and the NEW value. Statement 1: The value of the antique on ...”
April 18, 2018
Brent@GMATPrepNow posted a reply to 200 is what percent of 40? in the Problem Solving forum
“Let p = the percent So, we get: 200 = p percent of 40 Rewrite as: 200 = (p/100)(40) So, we get: 200 = (40p)/100 Simplify right side: 200 = (2p)/5 Multiply both sides by 5 to get: 1000 = 2p Solve: p = 500 Answer: E Cheers, Brent”
April 18, 2018
Brent@GMATPrepNow posted a reply to A certain office supply store stocks 2 sizes of in the Problem Solving forum
“There are two different cases to consider: 1) All 3 pads the same color 2) The 3 pads are 3 different colors Case 1: All 3 pads the same color Take the task of packaging pads and break it into stages. Stage 1: Select a size There are 2 possible sizes, so we can complete stage 1 in 2 ...”
April 18, 2018
Brent@GMATPrepNow posted a reply to A certain fruit stand sold apples for $0.70 each and in the Problem Solving forum “Here''s an approach where we test the POSSIBLE SCENARIOS. FACT #1: (total cost of apples) + (total cost of bananas) = 630 CENTS FACT #2: total cost of bananas is DIVISIBLE by 50, since each banana costs 50 cents. Now let''s start testing POSSIBLE scenarios. Customer buys 1 apple. 1 ...” April 17, 2018 Brent@GMATPrepNow posted a reply to In the quotient a/b positive, which of the following in the Problem Solving forum “Another approach... The key word here is MUST So, if we can find values of a and b that make an answer choice FALSE, then we can eliminate that answer choice. For example, a = -3 and b = -1 satisfies the given condition that a/b is positive Now take the answer choices and plug in a = -3 ...” April 17, 2018 Brent@GMATPrepNow posted a reply to In the quotient a/b positive, which of the following in the Problem Solving forum “GIVEN: a/b is positive This means that a and b have the SAME SIGN (e.g., both are negative or both are positive) Scan the answer choices.... Since a and b have the SAME SIGN, we know that the product ab must be positive Answer: C Cheers, Brent” April 17, 2018 Brent@GMATPrepNow posted a reply to If a two digit integer is divided by an integer formed by re in the Problem Solving forum “How about 89 divided by 98? 89 divided by 98 equals 0 with remainder 89 I don''t see 89 as an answer choice. Am I missing something? Cheers, Brent” April 17, 2018 beatthegmat posted a reply to Delete account? in the Suggestions and Feedback forum “bjedgert has been removed.” April 16, 2018 Brent@GMATPrepNow posted a reply to On Wednesday morning a fortune cookie machine ran in the Data Sufficiency forum “Target question: At what time did it completely fill the order that morning? For this work question, we need to know that time = (output)/(rate) Statement 1: The machine produces 300 units per hour. Okay, so we know the machine''s rate, but we don''t know anything about the size of the ...” April 16, 2018 Brent@GMATPrepNow posted a reply to A regular polygon can be constructed with a compass and in the Problem Solving forum “I agree with you, regor60. Cheers, Brent” April 16, 2018 Brent@GMATPrepNow posted a reply to Last year, Christine received 12 monthly paychecks. Each of in the Problem Solving forum “Another approach is to use weighted averages. Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ... In this question, the proportion of$4500 paychecks = 4/12 = 1/3 And the proportion ...”
April 15, 2018
Brent@GMATPrepNow posted a reply to Is standard deviation of Set A > standard deviation of Se in the Data Sufficiency forum
“Target question: Is standard deviation of Set A > standard deviation of Set B? Head straight to... Statements 1 and 2 COMBINED We can quickly come up with 2 cases that satisfy BOTH statements: Case a: Set A = {4, 4, 4, 4} and set B = {1, 2, 3}. Notice that both statements are ...”
April 15, 2018
Brent@GMATPrepNow posted a reply to For any real number x, the operator & is defined as in the Problem Solving forum
“Let''s look at a few examples of this operator (&) in action. If &(x) = x(1 − x), then... &(3) = 3(1 − 3) = 3(-2) = -6 &(7) = 7(1 − 7) = 7(-6) = -42 &(-5) = -5(1 − -5) = (-5)(6) = -30 And now..... &(p+1) = (p+1)(p+1)] = (p + 1)(-p) Now onto the ...”
April 15, 2018
Brent@GMATPrepNow posted a reply to What is the remainder when k^2 is divided by 8? in the Data Sufficiency forum
“Target question: What is the remainder when k² is divided by 8? Statement 1: When k is divided by 2, the remainder is 1. This tells us that k is one greater than some multiple of 2. So, we can write k = 2n + 1, where n is some integer. If k = 2n + 1, then k² = (2n + 1)² = 4n² + 4n + ...”
April 15, 2018
Brent@GMATPrepNow posted a reply to probability in the Problem Solving forum
“Your new question: Two people are randomly selected from the group of five people: Amir, Brian, Claudia, Dhana and Ebo. What is the probability that Amir & Brian are BOTH selected? The correct answer to that question is 1/10. You''re getting 2/10 as your answer, because you''re treating the ...”
April 14, 2018
Brent@GMATPrepNow posted a reply to Is positive integer n – 1 a multiple of 3? in the Data Sufficiency forum
“Target question: Is positive integer n – 1 a multiple of 3? Statement 1: n³ – n is a multiple of 3 Let''s do some FACTORING n³ – n = n(n² - 1) = n(n + 1)(n - 1) So, statement 1 tells us that n(n + 1)(n - 1) is a multiple of 3 Notice that (n-1), n and (n+1) are 3 CONSECUTIVE ...”
April 14, 2018
Brent@GMATPrepNow posted a reply to On a Monday in a certain restaurant, 20 percent of the in the Problem Solving forum
“On a Monday in a certain restaurant, 20 percent of the 180 customers ordered the daily special. 10% of 180 = 18 So, 20% of 180 = 36 So, 36 people ordered the daily special on MONDAY On Tuesday, only 10 percent of the 120 customers ordered the special. 10% of 120 = 12 So, 12 people ordered ...”
April 14, 2018
Brent@GMATPrepNow posted a reply to For the positive integers x, x + 2, x + 4, x + 7, and in the Problem Solving forum
“MEAN mean = x + 5 MEDIAN The 5 values are already arranged in ASCENDING order {x, x + 2, x + 4, x + 7, x + 12} So, the median = the middle value = x + 4 The mean is how much greater than the median? In other words x + 5 is how much greater than the x + 4? Answer = (x + 5) - (x + 4) = ...”
April 14, 2018
Brent@GMATPrepNow posted a reply to In a survey of 200 college graduates, 30 percent said in the Data Sufficiency forum
“We can solve this question using 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 college graduates, and the two characteristics are: - received ...”
April 13, 2018
Brent@GMATPrepNow posted a reply to If x > y, is x > 6 ? (1) (x - 7)(y - 7) = 0 (2) x > in the Data Sufficiency forum
“Target question: Is x > 6 ? Given: y < x Statement 1: (x - 7)(y - 7) = 0 There are two possible cases that make this equation true. Either x = 7 OR y = 7 Let''s examine each case: Case a: x = 7. In this case, the answer to the target question is YES, x IS greater than 6 Case b: ...”
April 13, 2018
Brent@GMATPrepNow posted a reply to When a positive integer n is divided by 5, the remainder is in the Data Sufficiency forum
“Target question: What is the remainder when n is divided by 3? Given: When positive integer n is divided by 5, the remainder is 2 ----ASIDE---------------------- 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 ...”
April 13, 2018
Brent@GMATPrepNow posted a reply to A train travels at the rate of 10 miles/hr for the first in the Problem Solving forum
“First check the answer choices (ALWAYS check the answer choice before deciding on an approach to a question) We see that all answer choices are between 8 hours and 10 hours. So, let''s test the answer choices, starting with 8 hours, and then go from there (if need be). A) 8 hours Distance ...”
April 13, 2018
beatthegmat posted a reply to Delete account? in the Suggestions and Feedback forum
“Happy to help. Your account has been deleted.”
April 12, 2018
Brent@GMATPrepNow posted a reply to Is x>0? in the Data Sufficiency forum
“Target question: Is x POSITIVE? Statement 1: (x + y )² > (x - y)² Take: (x + y )² > (x - y)² Expand and simplify both sides to get: x² + 2xy + y ² > x² - 2xy + y ² Subtract x² from both sides: 2xy + y ² > -2xy + y ² Subtract y² from both sides: 2xy > -2xy Add ...”
April 12, 2018
Brent@GMATPrepNow posted a reply to The arithmetic mean of the list of numbers in the Problem Solving forum
“The arithmetic mean of the list of numbers above is 4. So, (3 + k + 2 + 8 + m + 3)/6 = 4 Multiply both sides by 6 to get: 3 + k + 2 + 8 + m + 3 = 24 Simplify: 16 + k + m = 24 Subtract 16 from both sides to get: k + m = 8 If k and m are integers k ≠ m, what is the median of the list? ...”
April 12, 2018
Brent@GMATPrepNow posted a reply to A bag consists of 20 marbles, of which 5 are blue, 9 are red in the Problem Solving forum
“Your solution is perfect. If you''re looking for an alternate approach, one option is to use the complement: P(red or white) = 1 - P(NOT red or white) = 1 - P(blue) = 1 - 5/20 = 15/20 = 3/4 Answer: A”
April 11, 2018
beatthegmat posted a reply to Delete account in the Suggestions and Feedback forum
“Hi Dhinda, Your account has been deleted. Best, The BeatTheGMAT Team”
April 11, 2018
Brent@GMATPrepNow posted a reply to If a copier makes 3 copies every 4 seconds, then continues in the Problem Solving forum
“The above solution is perfect, but here''s another approach... We can apply some number sense in a series of steps GIVEN: Copier makes 3 copies every 4 seconds So: the copier makes 45 copies every 60 seconds In other words, the copier makes 45 copies every 1 MINUTE Keep going: the copier ...”
April 9, 2018
Brent@GMATPrepNow posted a reply to OG2015 DS If n + k = m in the Data Sufficiency forum
“I''d typically use the same approach that Ceilidh used, but here''s one more approach... Target question: What is the value of k? Given: n + k = m Statement 1: n = 10 Let''s TEST some values There are several values of m, n and k that satisfy statement 1. Here are two: Case a: m = ...”
April 9, 2018
Brent@GMATPrepNow posted a reply to value of y in the Problem Solving forum
“There are infinitely many right triangles that have an area of 1. So, one approach is to find a triangle that meets the given conditions, and see what conclusions we can draw. Here''s one such right triangle: https://s26.postimg.org/ctwnpq92d/image.png This meets the conditions that the ...”
April 9, 2018
Brent@GMATPrepNow posted a reply to Is a=−b? in the Data Sufficiency forum
“Target question: Is a = −b? This is a good candidate for rephrasing the target question. Aside: Here’s a video with tips on rephrasing the target question: Take the equation a = −b and add b to both sides to get: a + b= 0 So, we get.... REPHRASED target question: Is a + b= 0? ...”
April 8, 2018
Brent@GMATPrepNow posted a reply to During Thanksgiving weekend, a car rental company rented 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 vehicles, and the two characteristics are: ...”
April 8, 2018
Brent@GMATPrepNow posted a reply to Three gnomes and three elves sit down in a row of six... in the Problem Solving forum
“Your solution is perfect. It''s also how I would have solved it. Cheers, Brent”
April 7, 2018
Brent@GMATPrepNow posted a reply to Which expression is equivalent to (5x − 3y)^2? in the Problem Solving forum
“One option is to use the FOIL method to expand the product (that''s the solution I''d typically use) However, we can also use this approach: First recognize that we''re looking for an expression that''s EQUIVALENT to (5x − 3y)^2 for all values of x and y So, for example, let''s determine the ...”
April 7, 2018
Brent@GMATPrepNow posted a reply to OG2015 PS If x = 1- 3t in the Problem Solving forum
“GIVEN: x = 1- 3t y = 2t - 1 We want x = y Substitute to get: 1- 3t = 2t - 1 Add 3t to both sides: 1 = 5t - 1 Add 1 to both sides: 2 = 5t Divide both sides by 5 to get: 2/5 = t Answer: D Cheers, Brent”
April 7, 2018
Brent@GMATPrepNow posted a reply to A basketball coach will select the members of a five-player in the Problem Solving forum
“P(John and Peter both on the team) = (# of teams that include both John and Peter) / (total # of 5-person teams possible) a) # of teams that include both John and Peter - Put John and Peter on the team. This can be accomplished in 1 way - Select the remaining 3 team-members from the remaining 7 ...”
April 7, 2018
Brent@GMATPrepNow posted a reply to The number of stamps that Kaye and Alberto had were... in the Problem Solving forum
“One option is to solve the question using TWO VARIABLES. Let K = # of stamps K had after the exchange Let A = # of stamps A had after the exchange This means that K+10 = # of stamps K had before the exchange This means that A-10 = # of stamps A had before the exchange Note: Our goal is to ...”
April 4, 2018
Brent@GMATPrepNow posted a reply to Five years ago Jim was three times as old as Raoul in the Problem Solving forum
“Let R = Raoul''s PRESENT age So, R - 5 = Raoul''s age 5 YEARS AGO Five years ago .... Monica was six years older than Raoul was. So, (R - 5) + 6 = Monica''s age 5 YEARS AGO In other words, R + 1 = Monica''s age 5 YEARS AGO Five years ago Jim was three times as old as Raoul was So, 3(R - 5) ...”
April 3, 2018
beatthegmat posted a new topic called An Insider’s Guide to the GRE® General Test in the GMAT Strategy forum
“Are you getting ready for the GRE<sup>®</sup> General Test? The test has several smart features that can help you do your best, but you’ll still have to do your part. The more prepared you are, the more confident you will feel on test day. This overview of the test with tips and ...”
April 2, 2018
Brent@GMATPrepNow posted a reply to Is the product abcd negative? in the Data Sufficiency forum
“Target question: Is the product abcd negative? Statement 1: a < b < c < d This statement doesn''t FEEL sufficient, so I''ll TEST some values. There are several values of a, b, c, and d that satisfy statement 1. Here are two: Case a: a = -1, b = 1, c = 2 and d = 3. In this case, ...”
March 31, 2018
beatthegmat posted a reply to The early Greeks designed a mud-brick temple that mirrored t in the Sentence Correction forum
March 31, 2018
Brent@GMATPrepNow posted a reply to At a garage sale, all of the prices of the items sold were in the Problem Solving forum
“The price of the radio was the 15th highest price So, there were 14 items that were more expensive than the radio. In other words, if we listed all of the prices in ascending order, we''d get something like: ........... radio, X, X, X, X, X, X, X, X, X, X, X, X, X, X The price of the radio ...”
March 31, 2018
Brent@GMATPrepNow posted a reply to How many positive two-digit numbers yield... in the Problem Solving forum
“Your approach is perfect. I can''t think of a faster approach. Cheers, Brent”
March 31, 2018
Brent@GMATPrepNow posted a reply to PS Question: Division of money in the GMAT Math forum
“This, I believe, is a 700+ level question. Cheers, Brent”
March 31, 2018
Brent@GMATPrepNow posted a reply to Critical points method for inequality Is x^2 > 1/x? in the Data Sufficiency forum
“Target question: Is x² > 1/x ? Statement 1: x² > x First off, this inequality tells us that x ≠ 0 Second, we can conclude that x² is POSITIVE. So, we can safely divide both sides of the inequality by x² to get: 1 > 1/x If 1 > 1/x, then there are two possible cases: ...”
March 30, 2018
Brent@GMATPrepNow posted a reply to How many passengers can be seated on a plane with r rows, if in the Problem Solving forum
“d double seats will seat 2d passengers t triple seats will seat 3t passengers So, the total number of seats in ONE ROW = 2d + 3t The plane has a total of r rows. So, the TOTAL number of seats = r(2d + 3t) Check the answer choices....not there (at least not in the above form) Expand to get: ...”
March 30, 2018
Brent@GMATPrepNow posted a reply to If 50-√7<x<50+√7, then x=? in the Data Sufficiency forum
“Target question: What is the value of x? Given: 50 - √7 < x < 50 + √7 √4 = 2 √9 = 3 So, we can say that √7 = 2.something This means: 50 - 2.something < x < 50 + 2.something Simplify to get: 47.something < x < 52.something Statement 1: x is an odd ...”
March 30, 2018
Brent@GMATPrepNow posted a reply to Grammer in the Sentence Correction forum
“With NONE, we examine the part after NONE to see whether it''s singular or plural. Here we have "None of my friends" (plural), so we need plural ARE.... Cheers, Brennt”
March 30, 2018
Brent@GMATPrepNow posted a reply to PS Question: Division of money in the GMAT Math forum
“Another approach: This time, let K = the money REMAINING after Ann has received her portion AND after Bob has taken $4. At this point, Bob receives 1/3 of K, and Chloe gets the rest. This means that Chloe receives 2/3 of K Since Chloe receives$32, we can say that: (2/3)K = 32 Multiply ...”
March 30, 2018
Brent@GMATPrepNow posted a reply to PS Question: Division of money in the GMAT Math forum
“Note: we don''t need to consider Ann''s portion in the solution. Let K = the money remaining AFTER Ann has received her portion and then go from there. We''re told that, once we remove Bob''s portion, we have $32 for Chloe. So, we get K - Bob''s$ = 32 Bob receives $4 plus one-third of what ...” March 30, 2018 Brent@GMATPrepNow posted a reply to When 1/10 percent of 5,000 is subtracted from 1/10 of 5,000 in the Problem Solving forum “1/10 percent of 5,000 10% of 5,000 = 500 1% of 5,000 = 50 0.1% of 5,000 = 5 In other words, 1/10 percent of 5,000 = 5 1/10 of 5,000 1/10 of 5,000 = (1/10)(5,000) = 5000/10 = 500 DIFFERENCE = 500 - 5 = 495 Answer: D Cheers, Brent” March 29, 2018 Brent@GMATPrepNow posted a reply to Car X is 40 miles west of Car Y. Both cars are traveling in the Problem Solving forum “Here''s one approach: Let''s let Car X''s original position be the initial starting point. So, when Car X is at the initial starting point, Car Y has already traveled 40 miles. My word equation involves the conditions when Car X catches up to Car Y. At that point, we can say: Car X''s ...” March 29, 2018 Brent@GMATPrepNow posted a reply to In a sequence of 8 consecutive integers, how much greater is in the Problem Solving forum “Let''s test 8 consecutive integers How about: 1, 2, 3, 4, 5, 6, 7, 8 sum of the first four integers = 1 + 2 + 3 + 4 = 10 sum of the last four integers = 5 + 6 + 7 + 8 = 26 Difference = 26 - 10 = 16 Answer: C Cheers, Brent” March 29, 2018 Brent@GMATPrepNow posted a reply to In a stack of boards at a lumber yard, the 20th board in the Problem Solving forum “Let''s start from the bottom and work our way up: We''ll start with the 16th board counting from the bottom of the stack Right BELOW that 16th board, we have a board that we''ll call Larry. So, Larry is the 15th board counting from the bottom of the stack. So, starting from the bottom and ...” March 29, 2018 Brent@GMATPrepNow posted a reply to Health insurance Plan A requires the insured to pay$1000 or in the Problem Solving forum
“Here''s an algebraic approach: Let T = TOTAL COST Plan A: Person pays EITHER $1000 OR 0.5T, whichever is LESS Plan B: Person pays$300 plus 20% of anything over $300. In other words, the person pays$300 + 0.2(T - 300) Since Plan A has two different scenarios, we need to test both. That ...”
March 29, 2018
Brent@GMATPrepNow posted a reply to A certain plumber charges $92 for each job completed in the Data Sufficiency forum “Oops!!!!!!!!!!! ” March 27, 2018 Brent@GMATPrepNow posted a reply to Bob drives at an average rate of 50 mph from Berkeley... in the Problem Solving forum “Your solution is perfect! Cheers, Brent” March 27, 2018 beatthegmat posted a reply to Delete account? in the Suggestions and Feedback forum “Complete” March 27, 2018 Brent@GMATPrepNow posted a reply to Last year, for every 100 million vehicles that traveled on.. in the Problem Solving forum “We can use equivalent ratios to solve this. # cars/# accidents: 100,000,000/96 = 3,000,000,000/x Rewrite with exponents: 10⁸/96 = (3)(10⁹) /x Cross multiply to get: (10⁸)(x) = (3)(10⁹)(96) 96 is close enough to 100, so let''s replace 96 with 100 to get: (10⁸)(x) = (3)(10⁹)(100) ...” March 27, 2018 Brent@GMATPrepNow posted a reply to Is x < y? in the Data Sufficiency forum “Don''t subtract inequalities Doing so can yield erroneous statements. Consider this example: 5 < 6 0 < 9 When we subtract these inequalities , we get 5 - 0 < 6 - 9 Evaluate to get 5 < -3 (not true) Cheers, Brent” March 27, 2018 Brent@GMATPrepNow posted a reply to A code is to be made by arranging 7 letters. Three of the in the Problem Solving forum “-------ASIDE------------------------ When we want to arrange a group of items in which some of the items are identical, we can use something called the MISSISSIPPI rule. It goes like this: If there are n objects where A of them are alike, another B of them are alike, another C of them are alike, ...” March 27, 2018 Brent@GMATPrepNow posted a reply to A car traveled from Los Angeles to San Francisco in 6 hours in the Problem Solving forum “A car traveled from Los Angeles to San Francisco in 6 hours at an average rate of x miles per hour. Distance = (time)(rate) So, distance from Los Angeles to San Francisco = (6)(x) = 6x miles The car returned along the same route at an average rate of y miles per hour We know the distance = 6x ...” March 27, 2018 Brent@GMATPrepNow posted a reply to The probability that team A will not win the tournament is in the Problem Solving forum “The probability that team A will NOT win the tournament is 80% In other words, the probability that team A will NOT win the tournament is 0.8 So P(team A WILL win the tournament) = 1 - 0.8 = 0.2 The probability that team B will NOT win the tournament is 60% So P(team B WILL win the tournament) ...” March 26, 2018 Brent@GMATPrepNow posted a reply to Which of the following is the greatest? in the Problem Solving forum “From a strictly subjective standpoint, I think (1 + 2)^5 is pretty great <i class="em em-grimacing"></i> A. (1 + 2)^5 = (3)^5 = 243 B. 10^3 = 1,000 C. (1^2 + 2^2)^4 = (1 + 4)^4 = (5)^4 = 625 D. (2^2 + 2^2 + 2^2)^3 = (4 + 4 + 4)^3 = (12)^3 ASIDE: I won''t bother ...” March 26, 2018 Brent@GMATPrepNow posted a reply to The average of m, n, and p is q and the average q and r is s in the Problem Solving forum “Your algebraic approach is perfect. Another approach is the INPUT-OUTPUT approach. First find some values of m, n, p, q, r and s that satisfy all of the given information. For example, the following values satisfy all of the given information: m = 1, n = 1, p = 1, q = 1, r = 1 and s = 1 ...” March 26, 2018 Brent@GMATPrepNow posted a reply to How many ways can the five digits 3, 3, 4, 5, 6 be arranged in the Problem Solving forum “One approach here is to first IGNORE the restriction (about the 3''s not appearing together) and then subtract all of the outcomes that break that restriction. I''m sure someone will show that approach. Here''s another approach: Take the task of arranging the 5 digits and break it into ...” March 25, 2018 Brent@GMATPrepNow posted a reply to City X has a population 4 times as great as the population in the Problem Solving forum “A nice (fast) approach is to plug in some numbers that meet the given conditions. City Y has a population twice as great as the population of City Z Let''s say the population of City Z is 1 person This means the population of City Y is 2 people City X has a population 4 times as great as ...” March 25, 2018 Brent@GMATPrepNow posted a reply to A card shop contains 5 birthday cards, 5 holiday cards... in the Problem Solving forum “Let''s first rewrite our probability and then apply probability rules. P(All 3 cards the same type) = P(1st card is ANY type AND 2nd card matches type of 1st card AND 3rd card matches type of 1st card) = P(1st card is ANY type) x P(2nd card matches type of 1st card) x P(3rd card matches ...” March 25, 2018 Brent@GMATPrepNow posted a reply to OG 18 - DS- Q362 - How to solve it quickest? in the GMAT Math forum “One 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. Here, we have a population of people, and the two characteristics are: - member of Club X or not a member of Club ...” March 25, 2018 Brent@GMATPrepNow posted a reply to What is the average (arithmetic mean) of eleven 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 24, 2018 Brent@GMATPrepNow posted a reply to The product of all the prime numbers less than... in the Problem Solving forum “The numbers are very spread apart (each answer choice is 10 times greater than the next answer choice). This means we can be quite AGGRESSIVE with our estimation. One approach: We have the product (2)(3)(5)(7)(11)(13)(17)(19) Let''s see if we can group the numbers to get some approximate ...” March 24, 2018 Brent@GMATPrepNow posted a reply to If m and n are prime numbers, is the remainder when in the Data Sufficiency forum “Target question: When 3m is divided by n, is the remainder greater than 5? Given: m and n are prime numbers Statement 1: m < 10 Let''s TEST some values. There are several values of m and n that satisfy statement 1. Here are two: Case a: m = 2 and n = 7. Here 3m = 6, so 3m divided ...” March 24, 2018 Brent@GMATPrepNow posted a reply to Five Most Common Mistakes on GMAT Data Sufficiency in the Data Sufficiency forum “Great initiative! Here are 4 more videos related to possible Data Sufficiency mistakes: - Common Mistakes - Part I: https://www.youtube.com/watch?v=iACq36scVYQ - Common Mistakes - Part II: https://www.youtube.com/watch?v=yEBRAR5jXlY - Common GMAT Data Sufficiency Myths - Part I: ...” March 23, 2018 Brent@GMATPrepNow posted a reply to Pete has some apples. He sold 40% more than he ate... in the Problem Solving forum “Your approach is perfect! Once we know that x = 70/1.4, we have a few ways to evaluate this. Here''s one way.... x = 70/1.4 = 700/14 (I multiplied top and bottom by 10 to eliminate the decimal) = 100/2 (I divided top and bottom by 7) = 50 Cheers, Brent” March 23, 2018 Brent@GMATPrepNow posted a reply to The greatest common factor of two positive integers is X... in the Problem Solving forum “--------ASIDE---------------------- There''s a nice rule that says: (greatest common divisor of A and B)(least common multiple of A and B) = AB Example: A = 10 and B = 15 Greatest common divisor of 10 and 15 = 5 Least common multiple of 10 and 15 = 30 Notice that these values satisfy the above ...” March 23, 2018 Brent@GMATPrepNow posted a reply to In country Z, 10% of the people do not have a university... in the Problem Solving forum “I thought I''d point out that Jay''s and Mitch''s Double Matrix 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 people, and the two characteristics are: - has a university diploma or ...” March 23, 2018 Brent@GMATPrepNow posted a reply to A street vendor sells only hot dogs and hamburgers, and at.. in the Problem Solving forum “Here''s an approach that uses three variables. Let D = # of hotdogs the vendor STARTED with Let H = # of hamburgers the vendor STARTED with Let x = # of hotdogs sold At the beginning of the day has a ratio of two hot dogs for every one hamburger. So, D/H = 2/1 Cross multiply to get: D = ...” March 23, 2018 Brent@GMATPrepNow posted a reply to In a 40-mile trip, the first 20 miles were traveled in in the Problem Solving forum “Here''s one approach: The total distance is 40 miles, and we want the average speed to be 60 miles per hour. Average speed = (total distance)/(total time) So, we get: 60 = (40 miles)/(total time) Solve equation to get: total time = 2/3 hours So, the TIME for the ENTIRE 40-mile trip needs to ...” March 22, 2018 Brent@GMATPrepNow posted a reply to According to the directions on a packet of smoothie mix in the Problem Solving forum “Here''s a similar question to practice with: https://www.beatthegmat.com/cans-of-oj-concentrate-t281253.html Cheers ,Brent” March 22, 2018 Brent@GMATPrepNow posted a reply to Is a + b > c + d? in the Data Sufficiency forum “Target question: Is a + b > c + d ? Statement 1: a > c Since we have no information about b or d, we cannot determine whether a + b > c + d Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT Statement 2: d < b Since we have no ...” March 22, 2018 Brent@GMATPrepNow posted a reply to if d is a positive integer, is √d an integer ? in the Data Sufficiency forum “NOTE: I have added brackets to the question to avoid ambiguity. Asde: This is very similar to this question: http://www.beatthegmat.com/og-quant-review-ps-q31-t268233.html#688190 Target question: Is √d an integer? Given: d is a positive integer Statement 1: √(9d) is an ...” March 22, 2018 Brent@GMATPrepNow posted a reply to If the positive integer n is greater than 6, what is in the Data Sufficiency forum “Here''s another (longer!) approach (MItch''s solution is much nicer, but this one will also work) Target question: What is the remainder when n is divided by 6? Given: Positive integer n is greater than 6 Statement 1: When n is divided by 9, the remainder is 2. ...” March 22, 2018 Brent@GMATPrepNow posted a reply to Right triangle PQR is to be constructed in the xy-plane... in the Problem Solving forum “Take the task of building triangles and break it into stages. Stage 1: Select any point where the right angle will be (point P). The point can be selected from a 10x11 grid. So, there 110 points to choose from. This means that stage 1 can be completed in 110 ways. Stage 2: Select a point ...” March 21, 2018 Brent@GMATPrepNow posted a reply to If A and B are positive integers greater than 1 such that in the Problem Solving forum “Yes you are correct. The statement tells us that EITHER both integers are odd OR both integers are even. Cheers, Brent” March 21, 2018 Brent@GMATPrepNow posted a reply to |y - 1/2| < 11/2 in the Problem Solving forum “---------ASIDE----------------------------------------------- When solving inequalities involving ABSOLUTE VALUE, there are 2 things you need to know: Rule #1: If |something| < k, then –k < something < k Rule #2: If |something| > k, then EITHER something > k OR something < ...” March 21, 2018 Brent@GMATPrepNow posted a reply to If a mixture of ground meat consists of 2 pounds of veal... in the Problem Solving forum “We can use the WEIGHTED AVERAGE formula: Weighted average of groups combined = (group A proportion)(group A average) + (group B proportion)(group B average) + (group C proportion)(group C average) + ... When we COMBINE the meats, the TOTAL weight = 2 + 5 = 7 pounds. So, veal comprises 2/7 of ...” March 20, 2018 Brent@GMATPrepNow posted a reply to How many gallons of milk that is 10 percent butter-fat... in the Problem Solving forum “One option is to focus on the butter fat We begin with 8 gallons of milk that is 35 percent butter-fat So, the volume of butter fat = 35% of 8 = (0.35)(8) = 2.8 gallons of butter fat (to begin) Let x = number of gallons of milk that is 10 percent butter-fat to be added to the initial 8 ...” March 20, 2018 Brent@GMATPrepNow posted a reply to OG - SC Question 74 in the Sentence Correction forum “Important: When a sentence begins with a with noun modifier (as it does in the original sentence), stop at the comma and ask the question that the modifier raises So, once we read, Despite its covering the entire planet, we should stop and ask . . . "What covers the entire planet?" ...” March 19, 2018 Brent@GMATPrepNow posted a reply to In the past, most children who went sledding in the winter s in the Critical Reasoning forum “Summarize the argument.. PREMISE: Kids used to use wooden sleds PREMISE: 10 years ago, plastic sleds came PREMISE: plastic sleds are faster and harder to steer and slow PREMISE: more kids injured last year than 10 years ago CONCLUSION: plastic sleds are more dangerous Now, check each ...” March 19, 2018 Brent@GMATPrepNow posted a reply to In how many ways can two integers m and n, with m > n, be in the Problem Solving forum “A nice rule says: the number of integers from x to y inclusive equals y - x + 1 32 - 12 + 1 = 21 So, there are 21 numbers from which to choose NOTE: the order in which we select the numbers does not matter because, once we have selected the 2 numbers, we''ll let m equal the larger value (to ...” March 19, 2018 Brent@GMATPrepNow posted a reply to If S = {0, 4, 5, 2, 11, 8}, how much greater than the in the Problem Solving forum “To find the median, first arrange the values in ASCENDING ORDER: {0, 2, 4, 5, 8, 11} Since the set has an EVEN number values, the median will be the average of the two middlemost numbers. So, median = (4 + 5)/2 = 9/2 = 4.5 Mean = (sum of all values in the set)/(number of values in the set) = ...” March 19, 2018 Brent@GMATPrepNow posted a reply to Which of the following equations has a solution in common in the Problem Solving forum “Step 1: Solve the given equation: x² - 2x - 15 = 0 This is a quadratic set equal to zero, so let''s factor to get: (x - 5)(x + 3)=0 So, we have two solutions (roots): x = 5 or x = -3 Step 2: Solve the equations in the answer choices to see which one has a root (solution) of x = 5 or x = -3 ...” March 19, 2018 Brent@GMATPrepNow posted a reply to Given 2x + y + z = 3 and 5x + 3y + z = 8, what is the in the Problem Solving forum “Another approach is to look for values of x, y and z that satisfy BOTH equations (2x + y + z = 3 and 5x + 3y + z = 8). One set of values is x = 1, y = 1 and z = 0 (there are infinitely many sets of values that satisfy both equations) What is the value of x + y - z ? x + y - z = 1 + 1 - 0 = 2 ...” March 19, 2018 Brent@GMATPrepNow posted a reply to The average (arithmetic mean) of a professor's salary at in the Data Sufficiency forum “I think you''re missing some information above. Target question: Is the average salary of a professor at University D at least 25 percent higher than that for a professor at University M? NOTE: In order to determine the average salary of a professor, we need to know the amount spent on ...” March 19, 2018 Brent@GMATPrepNow posted a reply to Unable to improve in GMAT RC(Accuracy: 65%) in the Reading Comprehension forum “A lot of people struggle with the time constraints of the Verbal section. If you consistently run out of time on the Verbal section, I suggest that you look for certain questions to guess and skip. For example, if you find Assumption CR questions particularly difficult, you might skip any of these ...” March 18, 2018 Brent@GMATPrepNow posted a reply to Tom and Samuel are riding motorcycles down the highway in the Data Sufficiency forum “Target question: How many minutes before Tom is 3 miles ahead of Samuel? Given: Tom is now 2 miles ahead of Samuel Statement 1: Tom is traveling at 70 miles per hour and Samuel is traveling at 60 miles per hour. We don''t really need to apply answer formulas here. We need only ...” March 18, 2018 Brent@GMATPrepNow posted a reply to Having received his weekly allowance, John spent 3/5 of in the Problem Solving forum “Let w = John’s weekly allowance Having received his weekly allowance, John spent 3/5 of his allowance at the arcade If John spent 3/5 of his allowance, then he has 2/5 REMAINING So, (2/5)(w) = allowance REMAINING The next day he spent one third of his remaining allowance at the toy store ...” March 18, 2018 Brent@GMATPrepNow posted a reply to Unable to improve in GMAT RC(Accuracy: 65%) in the Reading Comprehension forum “Hi sd2611, What do you feel is the main barrier to RC questions for you? Do you have enough time to read the passage and answer the related questions? Do you find it difficult to summarize each paragraph in a concise manner? Are there issues with vocabulary? Or perhaps there are other ...” March 18, 2018 Brent@GMATPrepNow posted a reply to The ratio of the number of boys to the number of girls in in the Problem Solving forum “Another approach: There are 5 more girls than boys in the club Let G = # of girls in club So G-5 = # of boys in club The ratio of the number of boys to the number of girls in a certain school club is 3 to 4. We can write (G-5)/G = 3/4 Cross multiply: 4(G-5) = 3G Expand: 4G - 20 = 3G ...” March 18, 2018 Brent@GMATPrepNow posted a reply to The ratio of the number of boys to the number of girls in in the Problem Solving forum “One approach: The ratio of the number of boys to the number of girls in a certain school club is 3 to 4. So, some possible scenarios are: 3 boys and 4 girls 6 boys and 8 girls 9 boys and 12 girls . . . There are 5 more girls than boys in the club So, keep listing scenarios until we ...” March 18, 2018 Brent@GMATPrepNow posted a reply to If x and y are positive integers, and 1 is the greatest in the Problem Solving forum “Consider these two cases. case 1: x = 3 and y = 2. This satisfies the condition that 1 is the greatest common divisor of x and y In this case 2x = 2(3) = 6, and 3y = 3(2) = 6 So, the greatest common divisor of 2x and 3y is 6 case 2: x = 1 and y = 1. This satisfies the condition that 1 is ...” March 18, 2018 Brent@GMATPrepNow posted a reply to John and Peter are among the nine players a basketball... in the Problem Solving forum “We want: a) # of teams that include both John and Peter b) total # of 5-person teams possible a) # of teams that include both John and Peter Put John and Peter on the team (this can be accomplished in 1 way) Select the remaining 3 team-members from the remaining 7 players (this can be ...” March 17, 2018 Brent@GMATPrepNow posted a reply to Last Sunday a certain store sold copies of newspaper a for.. in the Problem Solving forum “If you''re not sure how to proceed with this question, or if you''re behind on time and you want to catch up, you can give yourself a 50-50 chance in about 10 seconds. To do so, we''ll see what happens when we use an EXTREME value for p. Say p = 100 In other words, 100% of the newspapers sold ...” March 16, 2018 Brent@GMATPrepNow posted a reply to Last Sunday a certain store sold copies of newspaper a for.. in the Problem Solving forum “Let''s use the INPUT-OUTPUT approach. Let''s say that Newspaper A accounted for 20% of all newspapers sold. In other words, p = 20 This means that Newspaper B accounted for 80% of all newspapers sold. The question asks us to find the value of r, the percentage of newspaper revenue from ...” March 16, 2018 Brent@GMATPrepNow posted a reply to If d denotes a decimal, is d ≥ 0.5? in the Data Sufficiency forum “Target question: Is d ≥ 0.5? Statement 1: When d is rounded to the nearest tenth, the result is 0.5. There are several values of d that satisfy statement 1. Here are two: Case a: d = 0.51 (we get 0.5 when 0.51 is rounded to the nearest tenth). In this case, the answer to the target ...” March 15, 2018 Brent@GMATPrepNow posted a reply to The rectangle A has a (width) and b (height) and another... in the Problem Solving forum “Hi AAPL, Your solution is perfect. Once we know that a = 3k, c = 2k, b = 3m and d = 2m, then... Area of rectangle A = ab = (3k)(3m) = 9km Area of rectangle B = cd = (2k)(2m) = 4km So, the ratio of the rectangle A''s area to the rectangle B''s = 9km/4km = 9/4 Answer: D Cheers, Brent” March 15, 2018 Brent@GMATPrepNow posted a reply to A committee of 2 people is to be selected out of in the Problem Solving forum “Here''s an approach that uses probability rules. We want P(select at least 1 preacher) 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 ...” March 15, 2018 beatthegmat posted a reply to Delete account? in the Suggestions and Feedback forum “pareshcs, your account has been successfully deleted.” March 15, 2018 beatthegmat posted a reply to Delete account? in the Suggestions and Feedback forum “hhjj, your account has been successfully deleted.” March 15, 2018 Brent@GMATPrepNow posted a reply to When positive integer x is divided by 20, the remainder is 8 in the Problem Solving forum “There''s a nice rule that say, "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 can write 53 = (10)(5) + 3 ...” March 14, 2018 Brent@GMATPrepNow posted a reply to Seven basketball teams play in a league against each other in the Problem Solving forum “Take the task of arranging the top 3 teams and break it into stages. Stage 1: Select the 1st place team There are 7 teams to choose from, so we can complete stage 1 in 7 ways Stage 2: Select the 2nd place team Since already selected a team in stage 1, there are now 6 teams remaining to ...” March 14, 2018 Brent@GMATPrepNow posted a reply to Health insurance Plan A requires the insured to pay$1000... in the Problem Solving forum
“Here''s an algebraic approach: Let T = TOTAL COST Plan A: Person pays EITHER $1000 OR 0.5T, whichever is LESS Plan B: Person pays$300 plus 20% of anything over $300. In other words, the person pays$300 + 0.2(T - 300) Since Plan A has two different scenarios, we need to test both. That ...”
March 14, 2018
Brent@GMATPrepNow posted a reply to In a given finance lecture, 30% of the students are finance in the Problem Solving forum
“This question can be solved using the Double Matrix method. Note: This technique can be used for most questions featuring a population in which each member has two criteria associated with it. Here, the criteria are: - Major (Finance or Non-Finance) - Gender (Female or Male) Since ...”
March 14, 2018
Brent@GMATPrepNow posted a reply to If (n+2)!= n!(an^2+bn+c), then abc=? in the Problem Solving forum
“First recognize that (n + 2)! = (n + 2)(n + 1)(n)(n - 1)(n - 2)(n - 3)....(3)(2)(1) = (n + 2)(n + 1)(n!) = (n!)(n + 2)(n + 1) The question tells us that (n + 2)! = n!(an² + bn + c) So, we can write: (n!)(n + 2)(n + 1) = n!(an² + bn + c) Divide both sides by n! to get: (n + 2)(n + 1) = an² ...”
March 14, 2018
Brent@GMATPrepNow posted a reply to Sentence Correction in the Sentence Correction forum
“This question is primarily about PRONOUN REFERENTS. In the original sentence, we have the pronoun it. What does this pronoun refer to? The pronoun refers to the TERM (word) “psychopath” So, if we replace the pronoun IT with its referent TERM “psychopath” we get.... (A) the TERM ...”
March 14, 2018
Brent@GMATPrepNow posted a reply to A grocery store sells apples by the pound. If the price per in the Problem Solving forum
“let C = CURRENT price per pound So, C - 1 = INCREASED price per pound If the price per pound is increased by $1,$12 will buy 0.4 pounds less of apples than if the price remains at the current level. Let''s first turn this statement into a word equation We can write: pounds of apples that can ...”
March 13, 2018
Brent@GMATPrepNow posted a reply to John and Marry were each paid x dollars in advance... in the Problem Solving forum
“The problem with your solution is highlighted above in green In order for their hourly wages to be the same, we need (x - y)/8 = (x + y)/10 We need this because hourly wage = (total \$ received)/(total hours worked) For more on this, see my solution below. Cheers, Brent”
March 13, 2018
Brent@GMATPrepNow posted a reply to John and Marry were each paid x dollars in advance... in the Problem Solving forum
“Salary Mary''s NET salary was x - y dollars (because Mary gave John y dollars) John''s NET salary was x + y dollars Hours worked Mary worked 8 hours John worked 10 hours In the end, John and Mary received the SAME hourly wage. So, John''s hourly wage = Mary''s hourly wage Hourly ...”
March 13, 2018
Brent@GMATPrepNow posted a reply to Of the 300 employees of a certain company, 65 are... in the Problem Solving forum
“So, there are 300 employees and 235 of them are NOT accountants. We can also solve the question by applying probability rules P(neither selection is an accountant) = P(1st selection is not an accountant AND 2nd selection is not an accountant) = P(1st selection is not an accountant) x P(2nd ...”
March 12, 2018
Brent@GMATPrepNow posted a reply to A jury pool consists of 6 men and w women. If 2 jurors are s in the Data Sufficiency forum
“Target question: Is P(2 men) greater than P(1 man and 1 woman)? Statement 1: w> 3 Let''s see what happens if w = 3 (note: this is the best chance that P(2 men) will be greater than P(1 man and 1 woman) P(2 men) = P(man selected 1st and man selected 2nd) = (6/9)(5/8) = 30/72 P(1 man ...”
March 12, 2018
Brent@GMATPrepNow posted a reply to How many times will the digit 7 be written when listing the in the Problem Solving forum
“Here''s one way to look at it. Write all of the numbers as 3-digit numbers. That is, 000, 001, 002, 003, .... 998, 999 NOTE: Yes, I have started at 000 and ended at 999, even though though the question asks us to look at the numbers from 1 to 1000. HOWEVER, notice that 000 and 1000 do not ...”
March 12, 2018
Brent@GMATPrepNow posted a reply to A and B ran, at their respective rates, a race of 480m... in the Problem Solving forum
“Here''s one approach. . . Let A = A''s speed in meters per second Let B = B''s speed in meters per second A gives B a head start of 48 m and beats him by 1/10th of a minute. 1/10th of a minute = 6 seconds A''s travel time is 6 seconds less than B''s travel time So, (A''s travel time) = ...”
March 12, 2018
Brent@GMATPrepNow posted a reply to If x + y > 0, is xy^2 + x^2y > 0? in the Data Sufficiency forum
“ Given: x + y > 0 Target question: Is xy² + x²y > 0 This is a good candidate for rephrasing the target question. Aside: Here’s a video with tips on rephrasing the target question: Take the inequality: xy² + x²y > 0 Factor to get: xy(y + x)> 0 Since it is GIVEN ...”
March 12, 2018
Brent@GMATPrepNow posted a reply to A box contains one dozen donuts. Four of the donuts are... in the Problem Solving forum
“P(both are jelly) = P(1st selection is jelly AND 2nd selection is jelly) = P(1st selection is jelly) x P(2nd selection is jelly) = 4/12 x 3/11 = 1/11 Answer: A Cheers, Brent”
March 12, 2018
Brent@GMATPrepNow posted a reply to What is the value of the positive integer m? in the Data Sufficiency forum
“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 are: 1, 1+5, 1+(2)(5), 1+(3)(5), ...”
March 12, 2018
Brent@GMATPrepNow posted a reply to Which of the following is a factor of 1001^32 -1 in the Problem Solving forum
“The key to answering this question is to recognize that 1001^32 − 1 is a difference of squares And so it 1001^16 - 1 And 1001^18 - 1 etc 1001^32 − 1 = (1001^16 + 1)(1001^16 - 1) = (1001^16 + 1)(1001^8 + 1)(1001^8 - 1) = (1001^16 + 1)(1001^8 + 1)(1001^4 + 1)(1001^4 - 1) = (1001^16 + ...”
March 9, 2018