# sidceg

Brent@GMATPrepNow posted a new topic called Set A = {22, 27, 11, 12, 2}, and set B: {14, 19, 3, 4, x} in the Problem Solving forum
“Set A = {22, 27, 11, 12, 2}, and set B: {14, 19, 3, 4, x} If x < 0, and the standard deviation of set A = the standard deviation of set B, what is the value of x? A) -2 B) -3 C) -4 D) -5 E) -6 Difficulty level: 600-650 Answer: E Source: www.gmatprepnow.com”
Yesterday
Brent@GMATPrepNow posted a reply to x, y and p are integers, and xyp ≠ 0. in the Problem Solving forum
“Two important rules: ODD exponents preserve the sign of the base. So, (NEGATIVE)^(ODD integer) = NEGATIVE and (POSITIVE)^(ODD integer) = POSITIVE An EVEN exponent always yields a positive result (unless the base = 0) So, (NEGATIVE)^(EVEN integer) = POSITIVE and (POSITIVE)^(EVEN integer) ...”
Yesterday
GMATGuruNY posted a reply to Working together at their respective constant rates, Machine in the Problem Solving forum
“The prompt should read as follows: Since A+B take 8 hours to produce 1200 units, the combined rate for A+B = w/t = 1200/8 = 150 units per hour. Since B take 50% more time than the 8 hours required when A+B work together, B''s time = 8 + (50% of 8) = 8 + 4 = 12 hours. Since B takes 12 ...”
Yesterday
Brent@GMATPrepNow posted a new topic called x, y and p are integers, and xyp ≠ 0. in the Problem Solving forum
“x, y and p are integers, and xyp ≠ 0. If p^x < p^y, which of the following MUST be true? i) x − y < 0 ii) x < 2y iii) x^p < y^p A) i only B) ii only C) iii only D) i and ii only E) none of the above Difficulty level: 650-700 Answer: E Source: ...”
July 15, 2019
Brent@GMATPrepNow posted a reply to Five friends play blackjack in Las Vegas and lose an average in the Problem Solving forum
“Let A, B, C, D and E represent the LOSSES (in dollars) of the 5 friends Five friends play blackjack in Las Vegas and lose an average of $100 each. So, we can write: (A+B+C+D+E)/5 = 100 Multiply both sides by 5 to get: A+B+C+D+E = 500 If the losses of two of the friends total$380, what is ...”
July 15, 2019
GMATGuruNY posted a reply to Tom painted 1/3 of a wall red, 1/5 of the wall blue and the in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the total area. When the correct answer is plugged in, the area painted black = 238. Since 1/3 of the wall is painted red, it is almost certain that correct answer is a multiple of 3. For an integer to be a multiple of 3, its digit sum must be a ...”
July 15, 2019
GMATGuruNY posted a reply to There are three varieties of sugar in a store. Sugar S1 in the Data Sufficiency forum
“Statement 1: Case 1: A=10 kg and B=10 kg, for a total of 20 kg In this case, A=B, so the answer to the question stem is NO. Case 2: A=11 kg and B=9 kg, for a total of 20 kg In this case, A>B, so the answer to the question stem is YES. Since the answer is NO in Case 1 but YES in Case 2, ...”
July 14, 2019
Brent@GMATPrepNow posted a reply to If k is an integer and 2 < k < 7, for how many differe in the Problem Solving forum
“IMPORTANT RULE: If two sides of a triangle have lengths A and B, then . . . DIFFERENCE between A and B < length of third side < SUM of A and B We''re told that the two KNOWN sides have lengths 2 and 7 So, we can write: (7 - 2) < k < (7 + 2) Simplify: 5 < k < 9 Since k is an ...”
July 14, 2019
GMATGuruNY posted a reply to In the figure shown, what is the value of x? in the Data Sufficiency forum
“Neither statement alone is sufficient to determine the value of x. When we combine the two statements, here''s an efficient way to determine whether we have sufficient information. 1. Plug in values for all of the angle measurements, satisfying the constraints in the problem and the rules of ...”
July 14, 2019
Brent@GMATPrepNow posted a reply to For the 5 days shown in the graph, how many kilowatt-hours in the Problem Solving forum
“Where''s the graph? Cheers, Brent”
July 13, 2019
Brent@GMATPrepNow posted a reply to If x and y are both integers greater than 1, is x a multiple in the Data Sufficiency forum
“Target question: Is x a multiple of y? Asking whether x is a multiple of y is the same as asking whether x = (y)(some integer) For example, 12 is a multiple of 3 because 12 = (3)(4) So, let''s rephrase the question as... REPHRASED target question: Does x = (y)(some integer)? Statement 1: ...”
July 12, 2019
Brent@GMATPrepNow posted a reply to In how many different ways can 3 identical green shirts and in the Problem Solving forum
“We can take this question and ask an easier question: In how many ways can we choose 3 of the 6 children to receive a green shirt? Notice that, once we have given a green shirt to each of those 3 chosen children, the remaining children must get red shirts. In other words, once we have given ...”
July 12, 2019
Brent@GMATPrepNow posted a reply to Bill took 4 math tests, and each test received a score out in the Data Sufficiency forum
“Target question: What was Bill''s average (arithmetic mean) score for all 4 tests? Statement 1: Bill''s first 3 tests received an average score of 50. Since we don''t have any information about the 4th test, statement 1 is NOT SUFFICIENT Statement 2: Bill''s last 2 tests received an ...”
July 12, 2019
Brent@GMATPrepNow posted a reply to Did Insurance Company $$K$$ have more than $300 million in in the Data Sufficiency forum “Target question: Did Insurance Company $$K$$ have more than$300 million in total net profits last year? Jump straight to... . . . Statements 1 and 2 combined Statement 2 tells us about profits from ONE PART of Company K''s business. Statement 1 tells us a tiny bit about Company K''s ...”
July 12, 2019
GMATGuruNY posted a reply to Between the first day of May and last day in June, the price in the Problem Solving forum
“We can PLUG IN THE ANSWERS. When the correct answer is plugged in, Blue''s resulting price and Melange''s resulting price will be EQUAL. D: 100 Here, Blue''s initial price is 100% of Melange''s initial price, implying that the two initial prices are equal. Let Blue = May = $100. From May to ...” July 12, 2019 GMATGuruNY posted a reply to What is the remainder when a is divided by 4? in the Data Sufficiency forum “Statement 1: An odd integer can be written as follows: 2x+1, where x is an integer. Since a is the square of an odd integer, we get: a = (2x+1)² = (2x)² + 2(2x)(1) + 1² = 4x² + 4x + 1 = 4(x²+x) + 1 = (multiple of 4) + 1 Since a is equal to 1 more than a multiple of 4, dividing a by 4 will ...” July 11, 2019 Brent@GMATPrepNow posted a reply to a, b, c, d satisfy a-1=b+2=c-3=d+4. Which of a, b, c, d is t in the Problem Solving forum “Rewrite each value in terms of the same variable. Given: a - 1 = b + 3 Subtract 3 from both sides to get: b = a - 4 Given: a - 1 = c - 3 Add 3 to both sides to get: c = a + 2 Given: a - 1 = d + 4 Subtract 4 from both sides to get: d = a - 5 So, a, b, c and d are equal to a, a-4, a+2 ...” July 10, 2019 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Data Sufficiency lesson #8: - Choosing Good Numbers Video: https://www.youtube.com/watch?v=bu-WhqM0j1Q Cheers, Brent” July 9, 2019 GMATGuruNY posted a reply to If m and n are positive integers and r is the remained when in the Data Sufficiency forum “5(10^n) = 5 followed by n zeros. If n=1, then 5(10^n) = 5*10¹ = 5 followed by 1 zero = 50 If n=2, then 5(10^n) = 5*10² = 5 followed by 2 zeros = 500 If n=3, then 5(10^n) = 5*10³ = 5 followed by 3 zeros = 5000 Rule: An integer whose digits sum to a multiple of 3 is itself a multiple of 3. ...” July 9, 2019 GMATGuruNY posted a reply to What is 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56? in the Problem Solving forum “1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56 = 1/2 + (1/2 - 1/3) + (1/3 - 1/4) + (1/4 - 1/5) + (1/5 - 1/6) + (1/6 - 1/7) + (1/7 - 1/8) = 1/2 + 1/2 - 1/8 = 1 - 1/8 = 7/8 The correct answer is C.” July 9, 2019 Brent@GMATPrepNow posted a reply to A certain candy manufacturer reduced the weight of Candy Bar in the Problem Solving forum “Let''s assign nice values to the ORIGINAL weight and price of the candy bar. Let''s say it ORIGINALLY weight 100 ounces and cost$100 $1 per ounce If we decrease the weight be 20%, the NEW weight is 80 ounces. The price remains at$100 per bar So, the NEW price per ounce =$100/80 ounces = ...” July 8, 2019 Brent@GMATPrepNow posted a reply to While driving on the expressway, did Robin ever exceed the in the Data Sufficiency forum “NOTE: There''s nothing here to suggest that Robin''s speed was constant. Sure, she MIGHT have traveled at a constant speed, or her speed may have varied throughout the trip. Target question: Did Robin''s speed ever exceed 55 miles per hour? Statement 1: Robin drove 100 miles No information ...” July 8, 2019 Brent@GMATPrepNow posted a reply to What is the remainder when positive integer x is divided by in the Data Sufficiency forum “Target question: What is the remainder when positive integer x is divided by 5? Statement 1: x divided by 10 has a remainder of 7. There''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 divided by 5 equals 3 with ...” July 8, 2019 Brent@GMATPrepNow posted a reply to If x and y are greater than 0, is x = 1 ? in the Data Sufficiency forum “Target question: Is x = 1 ? Given: x and y are POSITIVE Statement 1: x/y = 1 Let''s 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. In this case, the answer to the target question is YES, x DOES equal 1 Case b: ...” July 8, 2019 Brent@GMATPrepNow posted a reply to The function f(a) is defined for all positive integers a as in the Problem Solving forum “Since 77 = (11)(7), any positive multiple of 7 or 11 will have a common factor with 77 where that common factor is greater than 1. For example, 77 and 14 share a common factor of 7. And 77 and 35 share a common factor of 7. Likewise, 77 and 55 share a common factor of 11. And 77 and 33 share ...” July 8, 2019 Brent@GMATPrepNow posted a reply to The table above shows the number of students in a certain in the Data Sufficiency forum “ASIDE: Since the diagram closely resembles a Double Matrix Method diagram, I''ll treat it as such. Target question: What is the total number of students in the class? Statement 1: Of the boys in the class, 15 are studying biology. Add this information to our diagram to get: ...” July 8, 2019 Brent@GMATPrepNow posted a reply to The table above shows the number of students in a certain in the Data Sufficiency forum “ASIDE: Since the diagram closely resembles a Double Matrix Method diagram, I''ll treat it as such. Target question: What is the total number of students in the class? Statement 1: Of the boys in the class, 15 are studying biology. Add this information to our diagram to get: ...” July 7, 2019 Brent@GMATPrepNow posted a reply to If x is a positive integer such that x^2 + 5x − 14 = 0, wh in the Problem Solving forum “GIVEN: x² + 5x − 14 = 0 Factor: (x + 7)(x - 2) = 0 So, EITHER x = -7 OR x = 2 Since we''re told x is POSITIVE, the correct answer is D Cheers, Brent” July 7, 2019 GMATGuruNY posted a reply to Inequalities :If x is an integer, what is the value of x? in the Data Sufficiency forum “In statement 1, |x²| is redundant: since x² cannot be negative, |x²| = x². Statement 1: |x-x²|=2 x - x² = ±2 x(1-x) = ±2. The resulting equation implies that x is a factor of ±2, yielding the following options: x=±1 or x=±2. Check which of these values are valid solutions for ...” July 7, 2019 GMATGuruNY posted a reply to What is the value of n in the equation: - 25 + 19 + n = s ? in the Data Sufficiency forum “What do we want? The value of n. Before we look at the statements, what do we have? A linear equation with two variables (n and s). To answer the question stem, what do we need? Another linear equation with one or both of the variables. Each statement gives us what we need and thus is ...” July 6, 2019 Brent@GMATPrepNow posted a reply to What is the value of n in the equation: - 25 + 19 + n = s ? in the Data Sufficiency forum “ Given: -25 + 19 + n = s Simplify: -6 + n = s Add 6 to both sides to get: n = s + 6 Target question: What is the value of n? Statement 1: s = 2 We already know that n = s + 6 Replace s with 2 to get: n = 2 + 6 = 8 The answer to the target question is n = 8 Since we can answer the ...” July 6, 2019 GMATGuruNY posted a reply to If a coin has an equal probability of landing heads up or in the Problem Solving forum “P(HHT) = 1/2 * 1/2 * 1/2 = 1/8. Since T can occur on the 1st, 2nd or 3rd flip, we multiply by 3: 3(1/8) = 3/8 = 0.375 The correct answer is C.” July 6, 2019 Brent@GMATPrepNow posted a reply to The price of a phone call consists of a standard connection in the Problem Solving forum “BTW, you posted the same question in January: https://www.beatthegmat.com/the-price-of-a-phone-call-consists-of-a-standard-connection-t305974.html Cheers, Brent” July 5, 2019 Brent@GMATPrepNow posted a reply to The price of a phone call consists of a standard connection in the Problem Solving forum “Let C = price of connection fee Let M = the price PER MINUTE A 10-minute call costs$2.90 We can write: C + 10M = 2.90 A 16-minute call costs $4.40. We can write: C + 16M = 4.40 How much does a 13-minute call cost? So far, we have: C + 10M = 2.90 C + 16M = 4.40 ONE (slower) ...” July 5, 2019 Brent@GMATPrepNow posted a reply to A certain family has 3 sons: Richard is 6 years older than in the Problem Solving forum “We can also solve this with 1 variable David is 8 years older than Scott Let x = Scott''s age NOW So, x + 8 = David''s age NOW Richard is 6 years older than David If x + 8 = David''s age NOW, then... (x + 8) + 6 = Richard''s age NOW In other words, x + 14 = Richard''s age NOW In in 8 ...” July 4, 2019 GMATGuruNY posted a reply to The British Admiralty and the War Office in the Sentence Correction forum “Neuroscientists are now drawing solid conclusions about the disease. Here, the disease serves as the object of the preposition about. A clause includes both a subject and a verb. A clause may function as a noun. SC720 in the OG18: Neuroscientists are now drawing solid conclusions about how ...” July 4, 2019 GMATGuruNY posted a reply to What is the number of solutions of x = |x-|30-2x||? in the Problem Solving forum “|x-|30-2x|| = x if the blue portion is equal to x or -x. Case 1: x-|30-2x| = x 0 = |30-2x| The equation above is valid if 30-2x=0: 30-2x = 0 30 = 2x 15 = x Case 2: x-|30-2x| = -x 2x = |30-2x| Case 2a: 2x = 30-2x 4x = 30 x = 30/4 = 7.5 Case 2b: -2x = 30-2x 0 = 30 Not valid. ...” July 4, 2019 Brent@GMATPrepNow posted a reply to When the positive integer x is divided by 11, the quotient 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 3, 2019 Brent@GMATPrepNow posted a reply to A palindrome, such as 12321, is a number that remains the sa in the Problem Solving forum “If a number is divisible by 4, then the number created by the last 2 digits is divisible by 4. For example, we know that 76512, 311,244 and 2128 are divisible by 4 because 12, 44, and 28 are divisible by 4 So, the last 2 digits of the 4-digit palindromes must be 00, 04, 08, 12, . . . , 92 or ...” July 3, 2019 GMATGuruNY posted a reply to The LCM of three numbers is four times their GCF. Which of in the Problem Solving forum “Try to prove that I, II and III DON''T have to be true. To disprove I -- which states that at least one number must be odd -- let the GCF = 2. Since the LCM = 4(GCF), the LCM = 8. In this case: The greatest factor common of all three numbers must be 2. The least value divisible by all 3 ...” July 3, 2019 Brent@GMATPrepNow posted a reply to x, y and z are all unique numbers. If x is chosen randomly in the Problem Solving forum “Thanks Ian. Not sure how I missed "unique." Thanks for clarifying. Cheers, Brent” July 2, 2019 Brent@GMATPrepNow posted a reply to x, y and z are all unique numbers. If x is chosen randomly in the Problem Solving forum “Are the numbers chosen with or without replacement? For example, can y and z both be 23?” July 2, 2019 GMATGuruNY posted a reply to In addition to her work on the miocene homicide fossil in the Sentence Correction forum “A possessive such her may serve to refer to a preceding possessive. More importantly, her is a personal pronoun. Only a PERSON or PEOPLE may serve as referent for a personal pronoun (he, she, him, his, her). Since only a person or people may serve as referent for a personal pronoun -- and a ...” July 1, 2019 Brent@GMATPrepNow posted a reply to How many two-digit whole numbers yield a remainder of 1 when in the Problem Solving forum “...two-digit whole numbers yield a remainder of 1... Possible values are: 11, 21, 31, 41, 51, 61, 71, 81, and 91 ...and also yield a remainder of 1 when divided by 6 Take each value from 11, 21, 31, 41, 51, 61, 71, 81, and 91, and see which ones leave a remainder of 1 when divided by 6 11, 21, ...” July 1, 2019 GMATGuruNY posted a reply to A palindrome, such as 12321, is a number that remains the sa in the Problem Solving forum “The difference between the two palindromes = 32. Since subtracting 32 from the 4-digit palindrome must yield a 3-digit palindrome. the 4-digit palindrome must be just a bit more than 1000. Test 1001: 1001 - 32 = 969 Success! Subtracting 32 from 1001 (a 4-digit palindrome) yields 969 (a 3-digit ...” July 1, 2019 Brent@GMATPrepNow posted a reply to Is it true that a > b? in the Data Sufficiency forum “Target question: Is a > b? Statement 1: 2a > 2b Divide both sides by 2 to get: a > b The answer to the target question is YES, a IS greater than b Since we can answer the target question with certainty, statement 1 is SUFFICIENT Statement 2: a + c > b + c Subtract b from ...” June 30, 2019 Brent@GMATPrepNow posted a reply to If sequence S has 120 terms, what is the 105th term of S? in the Data Sufficiency forum “Target question: What is the 105th term of S? Given: Sequence S has 120 terms Statement 1: The first term of S is −8. We have no information about the nature of the sequence. So, knowing the value of term 1 won''t help is determine the value of term 105 Since we cannot answer the ...” June 30, 2019 GMATGuruNY posted a reply to Ellipsis in comparison in the Sentence Correction forum “Since the red portion refers to the FUTURE -- the expected level in 2010 -- the verb should be in the future tense: a level that WILL BE more than one-third higher than was the level in 1990 From context, we know that a level refers to the expected level of carbon emissions in 2010. Since ...” June 30, 2019 GMATGuruNY posted a reply to The ratio of flour to water to sugar in a recipe is 7:4:1. T in the Problem Solving forum “Original ratio: F:W:S = 7:4:1 A new recipe calls for a doubling of the ratio of flour to water. Doubling F/W = 7/4, we get: 2 * 7/4 = 7/2 Resulting ratio: F:W:S = 7:2:1 A halving of the ratio of flour to sugar. Halving F/S = 7/1, we get: (1/2)(7/1) = 7/2 Resulting ratio: F:W:S = ...” June 30, 2019 GMATGuruNY posted a reply to Amy's grade was 90th percentile of the 80 grades for her in the Problem Solving forum “Alternate approach: In Amy''s 80-student class, her percentile = 90. In the 100-student class, 19 scores are higher than Amy''s, implying that 81 scores are lower. Thus: Amy''s percentile in the 100-student class = 81. Amy''s AVERAGE percentile for all 180 students = (80*90 + 100*81)/180 = ...” June 30, 2019 Brent@GMATPrepNow posted a reply to If a certain wheel turns at a constant rate of $$x$$ in the Problem Solving forum “We can solve the question using equivalent ratios Wheel turns at a constant rate of x revolutions per minute We can also say the wheel turns at a constant rate of x revolutions per 60 seconds In other words, # of revolutions/seconds elapsed = x/60 How many revolutions will the wheel make in ...” June 29, 2019 Brent@GMATPrepNow posted a reply to Leona bought a 1-year,$10,000 certificate of deposit that in the Problem Solving forum
“If the interest is at an ANNUAL rate of 8 percent compounded semiannually, then EVERY SIX MONTHS, we add 4% interest to the certificate. No need to apply the compound interest formula. It''s just as fast to make the 2 calculations. After 6 months, the value of the certificate = $10,000 + (4% of ...” June 28, 2019 Brent@GMATPrepNow posted a reply to A computer routine was developed to generate two numbers, in the Problem Solving forum “Check each answer choice... (A) (99, 10) √100 = 10 So, √99 is LESS THAN 10 In other words, 10 is GREATER THAN √99 So, answer choice A breaks the rule that says the second number must be less than or equal to the square root of the first" Answer: A Cheers, Brent” June 27, 2019 Brent@GMATPrepNow posted a reply to If Lucy walks to work at a rate of 4 miles per hour, but she in the Problem Solving forum “Let d = distance from home to work Average speed = (total distance traveled)/(total travel time) total distance traveled = d + d = 2d total travel time = travel time TO work + travel time FROM work time = distance/speed We get: total travel time = d/4 + d/6 = 3d/12 + 2d/12 = ...” June 26, 2019 Brent@GMATPrepNow posted a reply to Right triangle PQR is to be constructed in the xy-plane so 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 ...” June 26, 2019 GMATGuruNY posted a reply to -2 ≤ x ≤ -1 and 1 ≤ y ≤ 2. What is the greatest poss in the Problem Solving forum “(x+y)/x = 1 only if y=0. Since the range for y does not include 0, eliminate E. If x=-2 and y=1, then (x+y)/y = (-2+1)/-2 = 1/2. Since 1/2 is the greatest of the remaining answer choices, the correct answer is D.” June 26, 2019 Brent@GMATPrepNow posted a reply to If y= 4 + (x - 3)^2, then y is lowest when in the Problem Solving forum “KEY CONCEPT: In order to minimize the value of y, we must minimize the value of (x -3)² We know that (some number)² ≥ 0 So, the SMALLEST possible value of (some number)² is 0 Likewise, the SMALLEST possible value of (x -3)² is 0 (x -3)² = 0 when x = 3 Answer: D Cheers, Brent” June 25, 2019 Brent@GMATPrepNow posted a reply to In the figure shown, what is the value of x? in the Data Sufficiency forum “The diagram (aka figure) is missing.” June 25, 2019 Brent@GMATPrepNow posted a reply to For integers x and y, which of the following MUST be an in the Problem Solving forum “One approach: The question is asking us to determine which expression MUST be an integer for ALL integer values of x and y. So, let''s TEST a pair of values. Let''s plug in x = 1 and y = 1 If an expression evaluates to be a non-integer, we can ELIMINATE that answer choice. We get... ...” June 25, 2019 Brent@GMATPrepNow posted a reply to A certain basketball team that has played 2/3 of its games in the Problem Solving forum “Given: The team has played 2/3 of its games. The team has played 20 games. If 2/3 of the total number of games = 20, then the total number of games = 30. This means that there are 10 games remaining. We want the team to win at least 3/4 of its games. 3/4 of 30 = 22.5 So, in order to ...” June 25, 2019 GMATGuruNY posted a reply to A certain basketball team that has played 2/3 of its games in the Problem Solving forum “Games played thus far = 17 wins + 3 losses = 20. Since these 20 games constitute 2/3 of the total number of games, we get: 20 = (2/3)T 60 = 2T 30 = T Since the team must win at least 3/4 of these 30 games, it may lose at most 1/4 of these 30 games: (1/4)30 = 7.5 Implication: The total ...” June 25, 2019 GMATGuruNY posted a reply to What is the average (arithmetic mean) of all 5-digit numbers in the Problem Solving forum “For any set that is SYMMETRICAL ABOUT THE MEDIAN: average = median Number of integers that can be composed from the 5 given digits = 5! = 120. Since the number of integers is EVEN, the median will be equal to the average of the two middle values: ...53791, 53917, 53971, 57139, 57193, ...” June 25, 2019 GMATGuruNY posted a reply to Ashok and Brian are both walking east along the same path; in the Data Sufficiency forum “Let A = A''s rate and B = Brian''s rate. Ashok has to CATCH-UP by 30 miles. The CATCH-UP rate is equal to the DIFFERENCE between the two rates. If A = 3mph, while B = 2mph, then every hour A walks 1 more mile than B, with the result that every hour A catches up by 1 mile -- the DIFFERENCE ...” June 23, 2019 GMATGuruNY posted a reply to GMAT Official Guide 2019 The city of Workney in the Critical Reasoning forum “When the correct answer is negated, the conclusion will be invalidated. Conclusion: Selling 9 tokens for$10 will alleviate the burden on POOR PEOPLE. E, negated: More riders would regularly purchase 18 tokens at once than would purchase only 9 tokens at once. Since this negation tells us ...”
June 23, 2019
Brent@GMATPrepNow posted a reply to If 2xy + z = 9, what is the value of the positive integer z? in the Data Sufficiency forum
“ Given: 2xy + z = 9 Target question: What is the value of the positive integer z? Statement 1: xyz - z² = 0 Factor to get: z(xy - z) = 0 This means that EITHER z = 0 OR xy - z = 0 HOWEVER, we''re told that z is a POSITIVE integer, which means z ≠0 So, it must be the case that xy - ...”
June 22, 2019
Brent@GMATPrepNow posted a reply to What is the perimeter of isosceles triangle MNP? in the Data Sufficiency forum
“Target question: What is the perimeter of isosceles triangle MNP? Statement 1: MN = 16 No idea about the other 2 sides Statement 1 is NOT SUFFICIENT Statement 2: NP = 20 No idea about the other 2 sides Statement 2 is NOT SUFFICIENT Statements 1 and 2 combined Since we have an ...”
June 22, 2019
Brent@GMATPrepNow posted a reply to f x and y are positive, what is the value of y ? in the Data Sufficiency forum
“Target question: What is the value of y? Given: x and y are positive Statement 1: xy is the square of an integer. There are several values of x and y that satisfy this condition. Here are two: Case a: x = 1 and y = 1. Here xy = (1)(1) = 1, which is the square of an integer. In this ...”
June 21, 2019
Brent@GMATPrepNow posted a reply to Which of the following is an integer? I. 12! / 6! II. 12! / in the Problem Solving forum
“I. 12!/6! = (12)(11)(10)(9)(8)(7)(6)(5)(4)(3)(2)(1)/(6)(5)(4)(3)(2)(1) = (12)(11)(10)(9)(8)(7) = some integer II. 12!/8! = (12)(11)(10)(9)(8)(7)(6)(5)(4)(3)(2)(1)/(8)(7)(6)(5)(4)(3)(2)(1) = (12)(11)(10)(9) = some integer III. 12!/7!5! = ...”
June 21, 2019
Brent@GMATPrepNow posted a reply to The average salary of 15 people in the shipping department in the Problem Solving forum
“]The average salary of 15 people in the shipping department at a certain firm is $20,000 So, (sum of all 15 salaries)/15 =$20,000 Multiply both sides by 15 to get: sum of all 15 salaries = $300,000 The salary of 5 of the employees is$25,000 each and the salary of 4 of the employees is $16,000 ...” June 20, 2019 Brent@GMATPrepNow posted a reply to In how many different ways can 3 fiction books and 3 in the Problem Solving forum “Take the task of arranging the 6 books and break it into stages. Stage 1: Arrange the 3 fiction books in a row We can arrange n unique objects in n! ways So, we can arrange the 3 books in 3! ways (= 6 ways) So, we can complete stage 1 in 6 ways Stage 2: Arrange the 3 non-fiction books in ...” June 20, 2019 GMATGuruNY posted a reply to What is the value of 1 / (√2+√1) + 1 / (√3+√2) + 1/( in the Problem Solving forum “1/(√2+√1) = √2-√1) + (√3-√2) + (√4-√3) +...+ (√24-√23) + (√25-√24) The red values all cancel out, yielding the following: -√1 + √25 = -1 + 5 = 4 The correct answer is D.” June 20, 2019 Brent@GMATPrepNow posted a reply to Data sufficiency in the GMAT Math forum “Take: y = 1 + 1/x Rewrite as: y = x/x + 1/x Simplify: y = (x + 1)/x So, we''re looking for an answer choice that can be expressed as a fraction in which the numerator is 1 greater than the denominator. Answer: E Cheers, Brent” June 19, 2019 GMATGuruNY posted a reply to OG 2018 CR Q Political theorist: Even with in the Critical Reasoning forum “Since the correct answer must SUPPORT the conclusion that a national leader with such , the argument above seems best classified as a STRENGTHEN CR.” June 19, 2019 Brent@GMATPrepNow posted a reply to If is n is multiple of 5, and n=p^2*q where p and q are prim in the Problem Solving forum “Let''s test some values that satisfy the given conditions (n is multiple of 5, and n = p²q, where p and q are prime numbers) How about: p = 2 and q = 5. In this case, n = (2²)(5) = 20, and 20 is a multiple of 5, which satisfies the given condition. Now plug p = 2 and q = 5 into the ...” June 19, 2019 GMATGuruNY posted a reply to If is n is multiple of 5, and n=p^2*q where p and q are prim in the Problem Solving forum “Try to prove that four of the answer choices DO NOT have to be a multiple of 25. The correct answer will be the remaining answer choice. In order for n to be a multiple of 5, either p and/or q must be a multiple of 5. Since the goal is to prove that four of the answer choices do NOT have to ...” June 19, 2019 Brent@GMATPrepNow posted a new topic called If 3 different integers are randomly selected from the set { in the Problem Solving forum “If 3 different integers are randomly selected from the set {1, 2, 3, 4, 5, 6}, what is the probability that a triangle can be constructed so that its 3 sides have the lengths of the 3 selected numbers? A) 0.25 B) 0.3 C) 0.35 D) 0.40 E) 0.45 Source: www.gmatprepnow.com Difficulty level: ...” June 19, 2019 Brent@GMATPrepNow posted a reply to A certain zoo has mammal and reptiles and birds, and no in the Data Sufficiency forum “Target question: How many birds are in the zoo? Given: The ratio of mammals to reptiles to birds is 11: 8:5. Given this ratio, we could say that there are: 11x mammals 8x reptiles 5x birds for some value of x. Statement 1: there are twelve more mammals in the zoo than there are ...” June 19, 2019 GMATGuruNY posted a reply to What is the value of the following sum? 1/(1*2) + 1/(2*3) + in the Problem Solving forum “x = 1/(1*2) + 1/(2*3) + 1/(3*4) + 1/(4*5) + 1/(5*6) 60x = 60D.” June 19, 2019 Brent@GMATPrepNow posted a reply to If x, y and z are three different non-negative integers, whi in the Problem Solving forum “Nice work, Mitch! I created this question to illustrate the importance of checking the answer choices each time you analyze one of the statements. Here’s why: Once we know that statement i COULD be true (it''s true when x = 0, y = 1 and z = 2), we should check the answer choices…. ...” June 18, 2019 GMATGuruNY posted a reply to If x, y and z are three different non-negative integers, whi in the Problem Solving forum “i: |x−y| = |x+y| = |y−z| This statement is true if x=0, y=1 and z=2: |0-1| = |0+1| = |1-2| 1 = 1 = 1 Since the correct answer must include i, eliminate B and C. ii) x^y = y^z This statement is true if x=1, y=2 and z=0: 1^2 = 2^0 1 = 1 Since the correct answer must include ii, ...” June 18, 2019 GMATGuruNY posted a reply to Over the first x games of his basketball season, Martin in the Problem Solving forum “Since the seasonal average = 30 points per game, the total number of points must be a MULTIPLE OF 30. Over the first x games of his basketball season, Martin averaged 32 points per game. In his last game, he scored 14 points. Implication: 32x + 14 = MULTIPLE OF 30 32x = (MULTIPLE OF 30) - 14 ...” June 18, 2019 Brent@GMATPrepNow posted a reply to A certain machine produces 1,000 units of product P per hour in the Problem Solving forum “A certain machine produces 1,000 units in 1 hour So, the machine produces 24,000 units in 24 hours In other words, the machine produces 24,000 units in 1 DAY So, the machine produces (24,000)(7) units in 7 DAYS (20,000)(7) = 140,000 So, (24,000)(7) = some number greater than 140,000 ...” June 18, 2019 Brent@GMATPrepNow posted a new topic called If x, y and z are three different non-negative integers, whi in the Problem Solving forum “If x, y and z are three different non-negative integers, which of the following COULD be true? i) |x−y| = |x+y| = |y−z| ii) x^y = y^z iii) x³ + y³ = z³ A) i only B) ii only C) iii only D) i and ii E) i and iii Source; www.gmatprepnow.com Difficulty level: 700+ Answer: D” June 18, 2019 GMATGuruNY posted a reply to If |2x|>|3y|, is x >y? 1) x>0 2) y>0 in the Data Sufficiency forum “Statement 1: Test x=3. Plugging x=3 into |2x|>|3y|, we get: |2*3|>|3y| 6 > 3|y| |y| < 2 -2 < y < 2 Since x=3 and -2 < y < 2, we get: x > y. Test x=1/2. Plugging x=1/2 into |2x|>|3y|, we get: |2 * 1/2|>|3y| 1 > 3|y| |y| < 1/3 -1/3 < y < ...” June 18, 2019 GMATGuruNY posted a reply to How many arrangements of the letters A, C, C, E, N, T includ in the Problem Solving forum “Good arrangements = total arrangements - bad arrangements. Total arrangements: Number of ways to arrange 6 elements = 6!. But when an arrangement includes IDENTICAL elements, we must divide by the number of ways each set of identical elements can be ARRANGED. The reason: When the identical ...” June 18, 2019 GMATGuruNY posted a reply to If $$\frac{(ab)^2+3ab-18}{(a-1)(a-2)}=0$$ where $$a$$ and in the Problem Solving forum “The equation is valid only if (ab)²+3ab-18 = 0. I: b=1 Plugging b=1 into (ab)²+3ab-18 = 0, we get: a²+3a-18 = 0 (a+6)(a-3) = 0 a=-6 or a=3 This works. Since the correct answer must include I, eliminate B. II: b=2 Plugging b=2 into (ab)²+3ab-18 = 0, we get: 4a²+6a-18 = 0 2a²+3a-9 ...” June 18, 2019 Brent@GMATPrepNow posted a reply to If p is an integer greater than 1, is p a prime number? in the Data Sufficiency forum “ Given: p is an integer greater than 1 Target question: Is p a prime number? Statement 1: p is a factor of 13 13 has exactly two factors: 1 and 13 Since p > 1, we KNOW that p = 13 (which is prime) The answer to the target question is YES, p IS prime Since we can answer the target ...” June 17, 2019 Brent@GMATPrepNow posted a reply to How many ways are there to arrange the letters in the word 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, ...” June 17, 2019 Brent@GMATPrepNow posted a reply to If |2x + 5| = |3x − 2|, which of the following is a possib in the Problem Solving forum “If |x| = |y|, then either x = y OR x = -y GIVEN: |2x + 5| = |3x − 2| So, EITHER 2x + 5 = 3x − 2 OR 2x + 5 = -(3x − 2) Let''s solve each equation... Take: 2x + 5 = 3x − 2 We get: 5 = x - 2 Solve: x = 7 Check answer choices.....x = 7 is not there. Try the other equation: Take: ...” June 17, 2019 Brent@GMATPrepNow posted a reply to Is h^2 = h? in the Data Sufficiency forum “Target question: Is h² = h? Statement 1: h + h = h Subtract h from both sides to get: h = 0 If h = 0, then h² = h becomes 0² = 0 (WORKS!) The answer to the target question is YES, h² = h Since we can answer the target question with certainty, statement 1 is SUFFICIENT Statement 2: ...” June 17, 2019 Brent@GMATPrepNow posted a reply to Is z > 0.5? in the Data Sufficiency forum “Target question: Is z > 0.5 ? SCAN the statements to see we can jump straight to.... Statements 1 and 2 combined There are infinitely-many values of z that satisfy BOTH statements. . Here are two: Case a: z = 0.6. In this case, the answer to the target question is YES, z IS greater ...” June 17, 2019 Brent@GMATPrepNow posted a reply to What is the value of x? in the Data Sufficiency forum “Target question: What is the value of x? Statement 1: 5x + 3y = 15 Since this is a linear equation with infinitely many solutions. Here are two: Case a: x = 3 and y = 0. In this case, the answer to the target question is x = 3 Case b: x = 0 and y = 5. In this case, the answer to the target ...” June 17, 2019 Brent@GMATPrepNow posted a reply to If the average (arithmetic mean) of seven consecutive in the Problem Solving forum “Another approach: For any set of consecutive integers, mean = median. So, in this case, mean = median = k + 2 So, the three values that come AFTER k + 2 are k+3, k+4, and k+5 And the three values that come BEFORE k + 2 are k-1, k, k+1, k+2, k+3, k+4, k+5 The product of the greatest and ...” June 17, 2019 GMATGuruNY posted a reply to If the average (arithmetic mean) of seven consecutive in the Problem Solving forum “For any set of consecutive integers, average = median. Let the 7 integers be 1, 2, 3, 4, 5, 6, 7. Since k+2 = average = median = 4, k=2. Product of the greatest and least = 7*1 = 7. The correct answer must yield 7 when k=2. Only C works: k² + 4k - 5 = 2² + (4*2) - 5 = 7 The correct ...” June 17, 2019 GMATGuruNY posted a reply to In how many different ways can 3 fiction books and 3 in the Problem Solving forum “Case 1: The 3 fiction books appear to the left of the 3 nonfiction books Number of ways to arrange the 3 fiction books = 3! = 6 Number of ways to arrange the 3 nonfiction books = 3! = 6 To combine these options, we multiply: 6*6 = 36 Case 2: The 3 nonfiction books appear to the left of the 3 ...” June 17, 2019 GMATGuruNY posted a reply to Is x<0? 1) x^3+1<0 2) x^3+2x^2+x+2=0 in the Data Sufficiency forum “Statement 1: x³ + 1 < 0 x³ < -1 The resulting inequality will hold true only if x < 0. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: x³ + 2x² + x + 2 = 0 x²(x+2) + (x+2) = 0 (x+2)(x²+1) = 0 The blue factor is equal to 0 if x=-2. It is not possible ...” June 17, 2019 GMATGuruNY posted a reply to How many rectangles can be formed by connecting the grid poi in the Problem Solving forum “https://i.postimg.cc/k681TSrJ/lattice-six-by-five.png To form a rectangle, we must combine a HORIZONTAL LENGTH with a VERTICAL LENGTH: Horizontal length: Number of ways to choose a horizontal length of 1: AB, BC, CD, DE, EF, FG = 6 Number of ways to choose a horizontal length of 2: AC, BD, ...” June 17, 2019 GMATGuruNY posted a reply to If a fair 6-sided die is rolled three times, what is the in the Problem Solving forum “P(exactly n times) = P(one way) * all possible ways. Let T = 3 and N = not 3. P(one way): One way to get exactly one 3: TNN. P(T on the 1st roll) = 1/6. (Of the 6 possible rolls, one is 3.) P(N on the 2nd roll) = 5/6. (Of the 6 possible rolls, five are not 3.) P(N on the 3nd roll) ...” June 16, 2019 GMATGuruNY posted a reply to 10^25 – 560 is divisible by all of the following EXCEPT: in the Problem Solving forum “RULE: MULTIPLE OF X + MULTIPLE OF X = MULTIPLE OF X MULTIPLE OF X + NON-MULTIPLE OF X = NON-MULTIPLE OF X For an integer to be divisible by 3, its digit sum must be a multiple of 3. 10²⁵ - 560 = (100000...) - (560) = 99999...440 Sum of the digits = (9+9+9+9+9...) + (4+4+0) = (multiple ...” June 16, 2019 Brent@GMATPrepNow posted a reply to Of the first three dozen cookies baked at a bake shop on a in the Data Sufficiency forum “ Given: Of the first three dozen (36) cookies baked at a bake shop on a certain day, 1/3 were chocolate chip cookies. 1/2 of the remaining cookies that were baked that day were chocolate chip cookies, 1/3 of 36 = 12. So, 12 chocolate cookies were baked in the first round of baking. Let x = ...” June 15, 2019 Brent@GMATPrepNow posted a reply to List $$K$$ consists of seven numbers. Is the average in the Data Sufficiency forum “Target question: Is the average (arithmetic mean) of the seven numbers negative? Statement 1: Four of the seven numbers in list K are negative. There are several scenarios that satisfy statement 1. Here are two: Case a: List K = {-10, -10, -10, -10, 1, 1, 1}. Average = sum/7 = -37/7. The ...” June 15, 2019 Brent@GMATPrepNow posted a reply to A set of 15 different integers has median of 25 and a range in the Problem Solving forum “Let''s tackle this one step at a time. First, we have 15 different integers. We can let these 15 spaces represent the 15 numbers written in ascending order: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ If the median is 25, we can add this as the middle value: _ _ _ _ _ _ _ 25 _ _ _ _ _ _ _ Notice that 7 ...” June 15, 2019 GMATGuruNY posted a reply to At a certain picnic, each of the guests was served either a in the Data Sufficiency forum “Let D = the double-scoop guests and S = the single-scoop guests. What is value of D? Statement 1: Since 60% received a double-scoop, the remaining 40% received a single scoop. Thus: D/S = 60%/40% = 3/2 No way to solve for D. INSUFFICIENT. Statement 2: Since the D double-scoop guests ...” June 15, 2019 GMATGuruNY posted a reply to A set of 15 different integers has median of 25 and a range in the Problem Solving forum “Range = biggest - smallest. Thus: 25 = biggest - smallest. Smallest = biggest - 25. We can plug the answer choices into the equation above. Since we need the greatest possible integer that could be in the set, we should start with the greatest answer choice. Answer choice E: 50 Smallest ...” June 15, 2019 GMATGuruNY posted a reply to Mixture problem in the Problem Solving forum “2 liters of 25% solution are combined with 6 liters of 40% solution. Average percentage for the entire 8 liters = (2*25 + 6*40)/8 = 290/8 = 36.25. The closest answer is C. Alligation approach: Let V1 and V2 = the two vessels and M = the mixture. Step 1: Plot the three percents on a ...” June 15, 2019 Brent@GMATPrepNow posted a reply to 8, 5, x, 6 The median of the list of positive integers in the Problem Solving forum “Since there is an even number of values in the list, the median will be the AVERAGE of the two middlemost values (when all values are listed in ASCENDING order) Let''s the answer choices... A) If x = 3, then the values are {3, 5, 6, 8}, which means the median = (5 + 6)/2 = 5.5 NO GOOD. We ...” June 14, 2019 Brent@GMATPrepNow posted a reply to Will the first 10 volumes of a 20-volume encyclopedia fit in the Data Sufficiency forum “Target question: Will the first 10 volumes of a 20-volume encyclopedia fit upright in the bookrack shown above? Statement 1: x = 50 centimeters. We have no idea how THICK the first 10 volumes are. They COULD each be 1 mm thick, in which case the 10 volumes will easily fit in the 50 cm ...” June 14, 2019 Brent@GMATPrepNow posted a reply to For every integer $$k$$ from 1 to 10, inclusive the "k& in the Problem Solving forum “T = 1/2 - 1/4 + 1/8 - 1/16 + . . . Notice that we can rewrite this as T = (1/2 - 1/4) + (1/8 - 1/16) + . . . When you start simplifying each part in brackets, you''ll see a pattern emerge. We get... T = 1/4 + 1/16 + 1/64 + 1/256 + 1/1024 Now examine the last 4 terms: 1/16 + 1/64 + 1/256 + ...” June 14, 2019 Brent@GMATPrepNow posted a reply to Jim is twice as old as Fred ... in the Problem Solving forum “I''ve added the answer choices.... 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 ...” June 13, 2019 Brent@GMATPrepNow posted a reply to in terms of k and m 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 13, 2019
Brent@GMATPrepNow posted a reply to cd? 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 13, 2019
Brent@GMATPrepNow posted a reply to If f(x) = x^3 + 9, is f(x) positive? in the Data Sufficiency forum
“ Given: f(x) = x³ + 9 Target question: Is f(x) positive? Statement 1: x < −1 Let''s TEST some values. There are several values of x that satisfy statement 1. Here are two: Case a: x = -2. In this case, f(-2) = (-2)³ + 9 = (-8) + 9 = 1. So, the answer to the target question is ...”
June 13, 2019
Brent@GMATPrepNow posted a reply to In May Mrs Lee's earnings were 60 percent of the Lee family' in the Problem Solving forum
“Since we''re asked to find a PERCENT (and not an actual value), we can assign a nice value to the Lee family''s total income. In May Mrs Lee''s earnings were 60 percent of the Lee family''s total income Let''s say $100 = Lee family''s total income IN MAY This means$60 = Mrs Lee''s earnings ...”
June 13, 2019
Brent@GMATPrepNow posted a reply to Which of the following could be the median for a set of in the Problem Solving forum
“Since 20 < x < 80, we can see that, if we arrange the 5 numbers in ASCENDING order, we get two possible cases: case a: {x, 56, 86, 97, 98} case b: {56, x, 86, 97, 98} In both cases, the median is 86 Answer: B Cheers, Brent”
June 13, 2019
Brent@GMATPrepNow posted a reply to a, b and c are three distinct integers, greater than 1, such in the Problem Solving forum
“150 = (2)(3)(5)(5) There are three sets of 3 values (each greater than 1) that have a product of 150: {2, 3, 25} {3, 5, 50} {2, 5, 15} GIVEN: The greatest common divisor of any two numbers, among the three integers, is 1 The only set that meets this condition is {2, 3, 25} SUM = 2 + 3 + ...”
June 12, 2019
Brent@GMATPrepNow posted a reply to David drove to work at an average (arithmetic mean) speed of in the Problem Solving forum
“Let''s start with a "word equation" We can write: (David''s travel time TO work) + (David''s travel time FROM work) = 2 hours time = distance/speed Let d = the distance each way We can write: d/45 + d/60 = 2 To eliminate the fractions, multiply both sides by 180, the LCM of 45 ...”
June 12, 2019
Brent@GMATPrepNow posted a reply to If x and y are positive integers, are x and y consecutive? in the Data Sufficiency forum
“ Given: x and y are positive integers Target question: Are x and y consecutive? Statement 1: x+y=3 Since x+y=3 are x positive integers, we know that one number must be 1 and the other number must be 2. The answer to the target question is YES, x and y ARE consecutive Since we can ...”
June 12, 2019
GMATGuruNY posted a reply to It is known that (1.1)^{17} is approximately equal to 5.05. in the Problem Solving forum
“1,1¹⁷ ≈ 5 (1.1¹⁷)³ ≈ 5³ 1.1⁵¹ ≈ 125 Thus: 1.1⁵⁰ = a bit less than 125 The correct answer is D.”
June 12, 2019
GMATGuruNY posted a reply to sum of these 24 integers? in the Problem Solving forum
“For any set that is SYMMETRICAL ABOUT THE MEDIAN: sum = (count)(median) The set is composed of integers in the following ranges: 1234...1432 2134...2431 3124...3421 4123...4321. Each range contains the same number of integers. Thus, the median of the set is equal to the average of ...”
June 11, 2019
Brent@GMATPrepNow posted a reply to How many integers between in the Problem Solving forum
“We want to determine how many integers end in 13 For example, 324713, 324813, 324913, 325013, . . . etc. Recognize that, for every 100 consecutive integers, only 1 will end in 13. There are 133,900 integers between 324,700 and 458,600 (since 458,600 - 324,700 = 133,900) Of those 133,900 ...”
June 11, 2019
Brent@GMATPrepNow posted a reply to sum of these 24 integers? in the Problem Solving forum
“Since we''re adding 24 numbers, we know that: Six numbers will be in the form 1--- Six numbers will be in the form 2--- Six numbers will be in the form 3--- Six numbers will be in the form 4--- Let''s first see what the sum is when we say all 24 numbers are 1000, 2000, 3000 or 4000 The sum = ...”
June 11, 2019
June 11, 2019
GMATGuruNY posted a reply to In a certain deck of cards in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the least and greatest integers on the cards. D: least = 4, greatest = 14 (14)(next larger integer) = 14*15 = 210. Too big, since each possible product must be less than 200. Implication: The greatest integer must be LESS THAN 14. Eliminate ...”
June 11, 2019
Brent@GMATPrepNow posted a reply to A certain library 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” June 11, 2019 GMATGuruNY posted a reply to Is x^3-x^2+x-1 > 0? in the Data Sufficiency forum “A critical point occurs when the two sides of an equality are EQUAL. To determine the ranges where the left side is GREATER than the right side, test one value to the left and right of each critical point. x³ - x² + x - 1 > 0? x²(x-1) + (x-1) > 0 (x-1)(x²+1) > 0 The two sides are ...” June 11, 2019 Brent@GMATPrepNow posted a reply to rates in the Problem Solving forum “Let''s assign a nice value to x (a value that will work well with all of the numbers 3, 4 and 6. Let''s say x = 24 GIVEN: 4 machines make x units in 6 days This means 4 machines make 24 units in 6 days So, 4 machines make 4 units in 1 day So, 1 machine makes 1 unit in 1 day From here, ...” June 11, 2019 Brent@GMATPrepNow posted a reply to DS in the Data Sufficiency forum “Target question: Is b (the y-coordinate of the point on the line) positive? Given: Line k passes through the origin and through the point (a,b) Statement 1: The slope of line k is negative There are several lines and points that satisfy statement 1. Here are two: Case a: ...” June 11, 2019 Brent@GMATPrepNow posted a reply to In a certain pond in the Problem Solving forum “We can use equivalent ratios here. We''re told that the proportion of tagged fish in the 50-fish SAMPLE is equal to the the proportion of tagged fish in the ENTIRE pond. So, (# tagged fish in SAMPLE)/50 = (total # tagged fish)/(total # of fish in POND) Let x = # of fish in the entire ...” June 11, 2019 GMATGuruNY posted a reply to To celebrate a colleague's retirement, the T coworkers in an in the Problem Solving forum “The T coworkers in an office agreed to share equally the cost of a catered lunch. The lunch costs a total of X dollars. Let X=5 and T=5, implying that the original cost per worker = 5/5 =$1. S of the coworkers fail to pay their share. Which of the following represents the additional amount, ...”
June 11, 2019
Brent@GMATPrepNow posted a reply to In the multiplication above, # represents a single digit. in the Problem Solving forum
“We''re told that # times 512 equals two thousand and something. Well, 4 times 512 = two thousand and something. And 5 times 512 = two thousand and something. No other digits, when multiplied by 512 will give us two thousand and something So, let''s test 4 and 5 (answer choices C and D) If ...”
June 10, 2019
Brent@GMATPrepNow posted a reply to In the xy-plane shown, is the slope of the line L negative ? in the Data Sufficiency forum
“Target question: Is the slope of the line L negative ? After scanning the two statement, I see that we can jump straight to . . . Statements 1 and 2 combined The COMBINED statements tell us that line l passes through quadrants III and IV. There are several lines that satisfy BOTH ...”
June 10, 2019
Brent@GMATPrepNow posted a reply to If x ≠ −2, then 5x+10x+2=5x+10x+2 in the Problem Solving forum
“Approach #2: We''re asked to evaluate (find the value of) the given expression. Since all of the answer choices are constants (just numbers), we know that the given expression must evaluate to be ONE of the answer choices FOR ALL VALUES OF X. So, let''s test a value of x Try x = 1 We get: ...”
June 10, 2019
Brent@GMATPrepNow posted a reply to If x ≠ −2, then 5x+10x+2=5x+10x+2 in the Problem Solving forum
“(5x+10)/(x+2) = (5(x+2))/(x+2) = 5 Answer: D Cheers, Brent”
June 10, 2019
Brent@GMATPrepNow posted a reply to For any integers a and b, min(a, b) and max(a, b) denote in the Data Sufficiency forum
“Notice that min(3, 4) = 3 Notice that min(2, 2) = 2 Notice that min(1, 11) = 1 KEY PROPERTY: In general, we can say that, if min(a,b) = c, then we know that c ≤ a and c ≤ b Target question: What is max(y, 8)? Statement 1: min(9, x) = y This tells us that y ≤ 9 Let''s test ...”
June 10, 2019
Brent@GMATPrepNow posted a reply to From a group of 10 students, 7 girls and 3 boys, a teacher in the Problem Solving forum
“Take the task of arranging students and break it into stages. Stage 1: Select two girls Since the order in which we select the women does not matter, we can use combinations. We can select 2 girls from 7 girls in 11C2 ways (21 ways) So, we can complete stage 1 in 21 ways If anyone is ...”
June 10, 2019
GMATGuruNY posted a reply to When the integer n is divided by 6, the remainder is 3, Whic in the Problem Solving forum
“When the integer n is divided by 6, the remainder is 3. When we are given this wording, the smallest option for n is THE REMAINDER ITSELF. Test n=3 in the answer choices: (A) n – 3 = 3-3 = 0 (B) n + 3 = 3+3 = 6 (C) 2n = 2*3 = 6 (D) 3n = 3*3 = 9 (E) 4n = 4*3 = 12 Only D is not a ...”
June 10, 2019
GMATGuruNY posted a reply to A real estate investment firm began the year with 80% of its in the Problem Solving forum
“Let the total investment = $1000, implying that commercial holdings = 80% of 1000 =$800 and that residential holdings = 1000-800 = $200. Since the total$1000 investment grows by 3.5%, the total growth = 3.5% of 1000 = $35. Since the$800 in commercial holdings grows by 7%, the growth in ...”
June 9, 2019
GMATGuruNY posted a reply to In order to conserve the energy and heat in the Sentence Correction forum
“A: reducing the rate at which they burn energy so that it is 25 percent lower Since the penguins are REDUCING THE RATE, we know from context that it refers to the rate, conveying that THE RATE is lower. Regardless, an answer choice may be eliminated for pronoun ambiguity only if an alternate ...”
June 9, 2019
GMATGuruNY posted a reply to Ann deposited money into two new accounts, A and B. Account in the Data Sufficiency forum
“What is the value of 0.08B - 0.05A? Statement 1: B-A = 200 B = A+200 Case 1: A = $100 and B=$300, with the result that 0.08B - 0.05A = 0.08(300) - 0.05(100) = 24-5 = 19 Case 2: A = $200 and B=$400, with the result that 0.08B - 0.05A = 0.08(400) - 0.05(200) = 32-10 = 22 Since 0.08B-0.05A ...”
June 9, 2019
Brent@GMATPrepNow posted a reply to If 3 different integers are randomly selected from the integ in the Problem Solving forum
“I specifically created this question to illustrate the importance of calculating the denominator first (when using counting techniques to solve a probability question) There are two reasons why you should calculate the denominator first: 1) The denominator is almost always easier to calculate ...”
June 7, 2019
Brent@GMATPrepNow posted a reply to Puzzling probability question in the Problem Solving forum
“P(selecting a sibling pair) = P(select a business student with a sibling AND select a law student who is that business student''s sibling) = P(select a business student with a sibling) x P(select a law student who is that business student''s sibling) = 30/500 x 1/800 = 30/400,000 = 3/40,000 = ...”
June 6, 2019
Brent@GMATPrepNow posted a new topic called If 3 different integers are randomly selected from the integ in the Problem Solving forum
“If 3 different integers are randomly selected from the integers from 1 to 12 inclusive, what is the probability that a triangle can be constructed so that its 3 sides are the lengths of the 3 selected numbers? A) 3/8 B) 7/18 C) 19/44 D) 39/88 E) 11/24 Answer: C Source: ...”
June 6, 2019
Brent@GMATPrepNow posted a reply to GMAT Prep in the Problem Solving forum
“In the 4 months leading up to March, the company PRODUCES 4x rakes (4 months at x/month = 4x) On March 1, x/2 rakes are SHIPPED, leaving 3.5x rakes for which the company must pay storage fees. On April 1, x/2 rakes are SHIPPED, leaving 3x rakes for which the company must pay storage fees. ...”
June 5, 2019
Brent@GMATPrepNow posted a reply to VIC question -- picking numbers in the Problem Solving forum
“Originally, T people were to pay total cost of x dollars. So, each person pays x/T each. After S people drop out, there are T-S people to pay total cost of x dollars. So, each person pays x/(T-S) each. The additional amount that each must pay = New cost per person - original cost per ...”
June 5, 2019
Brent@GMATPrepNow posted a reply to Hotel California in the Problem Solving forum
“One option is to use the Double Matrix method. Here, we have a population of lightbulbs, and the two characteristics of each bulb are: - incandescent or fluorescent - on or off Since the questions asks us to find a certain PERCENT, let''s say that there are 100 bulbs altogether. So, we ...”
June 5, 2019
Brent@GMATPrepNow posted a reply to Of the 12 temporary employees in a certain company, 4 will in the Problem Solving forum
“Take the task of selecting the employees and break it into stages. Stage 1: Select the 3 women The order in which we select the women does not matter, so we can use combinations. We can select 3 women from 5 women in 5C3 ways (= 10 ways) Aside: If anyone is interested, here''s video on ...”
June 5, 2019
Brent@GMATPrepNow posted a reply to If k is 96% greater than its reciprocal, which of the follow in the Problem Solving forum
“k is 96% greater than its reciprocal The reciprocal of k is 1/k So, we can write: k = (1/k) + (96% of 1/k) In other words: k = (1/k) + 0.96(1/k) Simplify: k = 1.96(1/k) Simplify: k = 1.96/k Multiply both sides by k to get: k² = 1.96 Solve: k = 1.4 of k = -1.4 Rewrite as follows: k = 7/5 of ...”
June 5, 2019
Brent@GMATPrepNow posted a new topic called If k is 96% greater than its reciprocal, which of the follow in the Problem Solving forum
“If k is 96% greater than its reciprocal, which of the following is an integer? A) 3k/7 B) 3k/5 C) 5k/7 D) 5k/3 E) 7k/5 Source: www.gmatprepnow.com Difficulty level: 600-650 Answer: C”
June 4, 2019
GMATGuruNY posted a reply to The number line shown contains three points R, S, and T, in the Problem Solving forum
“Let R=-3, S=3 and T=6, implying that r=|-3|=3, s=|3|=3, and t=|6|=6. Average of R, S, and T = (-3+3+6)/3 = 2. The correct answer must yield 2 when r=3, s=3 and t=6. Only E works: (s + t - r)/3 = (3+6-3)/3 = 6/3 = 2 The correct answer is E.”
June 4, 2019
GMATGuruNY posted a reply to The principal feature of the redesigned checks is a series o in the Sentence Correction forum
“In the OA, the list of instructions includes THREE TYPES OF REMINDERS: a reminder TO WATCH a reminder TO COMPARE a reminder TO VIEW In option 2, the list of instructions seems to include the following three nouns: REMINDERS COMPARING VIEWING Thus, the intended meaning is not conveyed in ...”
June 3, 2019
GMATGuruNY posted a reply to Two pieces of fruit are selected out of a group of 8 pieces in the Data Sufficiency forum
“What is the value of P(BB)? Statement 1: From 8 pieces of fruit, the probability of picking an apple = A/8. After 1 of the A apples has been picked, the number of remaining apples = A-1. From the 7 remaining pieces of fruit, the probability of picking one of the A-1 remaining apples = ...”
June 3, 2019
Brent@GMATPrepNow posted a reply to Which of the following sets contains only factors of 45? in the Problem Solving forum
“Scan the answer choices....(C and D)..... 13 is NOT a factor of 45. ELIMINATE C By the process of elimination, the correct answer is D Cheers, Brent Scan the two remaining answer choices.... 7 is NOT a factor of 45. ELIMINATE A, B and E”
June 3, 2019
Brent@GMATPrepNow posted a reply to A company has two types of machines, type R and type S. in the Problem Solving forum
“Here''s another approach . . . When it comes to questions where we must complete an entire job, I often (not always) like to know what can be accomplished in 1 unit of time (in this case, 1 hour). Machine R can complete 1/36 of the job in 1 hour. Machine S can complete 1/18 of the job in 1 ...”
June 3, 2019
Brent@GMATPrepNow posted a reply to A company has two types of machines, type R and type S. in the Problem Solving forum
“One approach is to assign a "nice" value to the job. Say, the job is to make 36 widgets. R does a certain job in 36 hours This means that machine R''s rate is 1 widget/hour S does the job in 18 hours This means that machine S''s rate is 2 widgets/hour So, their combined rate ...”
June 3, 2019
Brent@GMATPrepNow posted a reply to If k^2 = m^2, which of the following must be true? in the Problem Solving forum
“The question asks us what MUST be true. So, if we can find a case where a statement is not true, we can eliminate that answer choice. So, for example, one solution to the equation (k² = m²) is k = 1 and m = 1 Now let''s check the answer choices. A. k = m. Test: 1 = 1. Works. Keep A. B. ...”
June 3, 2019
Brent@GMATPrepNow posted a reply to A company that ships boxes to a total of 12 distribution in the Problem Solving forum
“We need to be able to create AT LEAST 12 codes (to represent the 12 countries). Let''s test the options. Can we get 12 or more color codes with 4 colors? Let''s see . . . 1-color codes = 4 (since there are 4 colors) 2-color codes = We need to choose 2 colors from 4. This can be ...”
June 2, 2019
Brent@GMATPrepNow posted a reply to What is the total cost to make 7 long distance telephone in the Data Sufficiency forum
“When we SCAN the statements, we see the key phrase: at least This allows us to jump straight to... Statements 1 and 2 combined There are infinitely many scenarios that satisfy BOTH statements. Here are two: Case a: Each call was 2 minutes long, for a total of 14 minutes. At $0.32 per ...” June 1, 2019 GMATGuruNY posted a reply to The vertices of a rectangle in the standard (x,y) coordinate in the Problem Solving forum “To partition the rectangle into equal areas, the line must pass through the CENTER of the rectangle. To determine the x-coordinate of the center, take the average of the x-coordinates that form the base: (0+7)/2 = 3.5. To determine the y-coordinate of the center, take the average of the ...” June 1, 2019 GMATGuruNY posted a reply to 10 factories, working for h hours per day, can produce P in the Problem Solving forum “When the factories work for h hours per day, P cars are produced every 5 days, with the result that 2P cars are produced every 10 days. If the daily work-hours are CUT IN HALF -- to h/2 hours per day -- the number of days required for 2P cars will DOUBLE to 20. Since the time for 2P cars increases ...” June 1, 2019 GMATGuruNY posted a reply to Being a United States citizen since 1988 and born in Calcutt in the Sentence Correction forum “One purpose of the present perfect -- has/have + VERBed -- is to express a past action that affects the present. OA: Bharati Mukherjee...has lived in England and Canada. Conveyed meaning: At some time in the past, Bharati Mukherjet lived in England and Canada, and this past action somehow ...” May 31, 2019 Brent@GMATPrepNow posted a reply to Of the 60 animals on a certain farm, $$\frac{2}{3}$$ are in the Data Sufficiency forum “Target question: How many of the animals are cows? Given: Of the 60 animals in a certain farm, 2/3 are either pigs or cows Let P = # of pigs Let C = # of cows 2/3 of 60 = 40, so we can say that P + C = 40 Statement 1: The farm has MORE THAN twice as many cows as it has pigs. In other ...” May 31, 2019 GMATGuruNY posted a reply to If xy≠0, and 60% of x equals 87.5% of y, what is the value in the Problem Solving forum “60x = 87.5y 120x = 175y 120(x/y) = 175 12(x/y) = 17.5 The correct answer is D.” May 30, 2019 GMATGuruNY posted a reply to Last year, the price of a jar of peanut butter at a certain in the Problem Solving forum “The price of a jar of peanut butter at a certain store was P dollars and the price of a jar of jelly at the same store was J dollars, where J=2P. Let P = 10 and J = 20 This year, the price of peanut butter increased by 20% and the price of jelly decreased by 20% New P = 10 + (20% of 10) = 10 + ...” May 29, 2019 GMATGuruNY posted a reply to In the figure above, $$AB$$ is perpendicular to $$BC$$ and in the Problem Solving forum “Let ∆ABD and ∆CBD each be a 45-45-90 triangle with sides 1, 1 and √2: https://i.postimg.cc/JGVTHJg1/two-45-45-90-triangles.png For the figure above, only option B is true: 1/BD² = 1/BC² + 1/AB² 1/1² = 1/√2² + 1/√2² 1 = 1/2 + 1/2 1 = 1 The correct answer is B.” May 29, 2019 GMATGuruNY posted a reply to GMAT prep question-Confusing one ! in the Sentence Correction forum “To refer to a noun that takes a SINGULAR verb, we use amount. To refer to a noun that takes a PLURAL verb, we use number. A and C: in terms of flights, an equal amount Here, amount cannot serve to refer to flights (a noun that takes a plural verb). Eliminate A and C. E: an equal number as ...” May 29, 2019 Brent@GMATPrepNow posted a reply to A computer programmer needs to print 148 documents. The in the Problem Solving forum “We can also answer this question using a step-by-step approach based on number sense. IMPORTANT: The word approximately typically suggests that we can be somewhat aggressive with our estimation There are 148 documents and the documents have an average length of 10 pages So, the TOTAL number ...” May 29, 2019 Brent@GMATPrepNow posted a reply to x + 2y + 3z = 4 and 5x + 4y + 3z = 8. What is the value of x in the Problem Solving forum “GIVEN: x + 2y + 3z = 4 5x + 4y + 3z = 8 ADD the two equations to get: 6x + 6y + 6z = 12 Factor: 6(x + y + z) = 12 Divide both sides by 6 to get: x + y + z = 2 Answer: B Cheers, Brent” May 28, 2019 Brent@GMATPrepNow posted a reply to Two different primes may be said to"rhyme" around in the Problem Solving forum “If two numbers are rhyming primes, then the integer the rhyme around will be the AVERAGE of the two primes. For example, 3 and 7 rhyme around 5. Notice that the AVERAGE of 3 and 7 is 5. Likewise, 5 and 23 rhyme around 14, and the AVERAGE of 5 and 23 is 14. Now onto the solution... List ...” May 28, 2019 Brent@GMATPrepNow posted a reply to A certain fruit stand sold apples for$0.70 each and bananas 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 ...”
May 28, 2019
Brent@GMATPrepNow posted a reply to From a group of 5 managers (Joo, Kendra, Lee, Marnie, and in the Problem Solving forum
“Our goal is to find P(M and N both selected) There are two ways to approach this. Method #1: P(M and N both selected) = P(one of them is selected 1st AND the other selected 2nd) = P(one of them is selected 1st) x P(the other selected 2nd) = (2/5)(1/4) = 1/10 = 0.1 Aside: P(one of them ...”
May 28, 2019
GMATGuruNY posted a reply to if x and y are positive , is 4x>3y? in the Data Sufficiency forum
“Since y is POSITIVE, the inequalities can safely be divided by y. 4x > 3y x > (3/4)y x/y > 3/4 Question stem, rephrased: Is x/y > 3/4? Statement 1: x > y-x 2x > y 2(x/y) > 1 x/y > 1/2 Case 1: x/y = 2/3 In this case, x/y < 3/4, so the answer to the ...”
May 28, 2019
GMATGuruNY posted a reply to A certain fruit stand sold apples for $0.70 each and bananas in the Problem Solving forum “Consider the following equation: 2x + 3y = 30. If x and y are nonnegative integers, the following solutions are possible: x=15, y=0 x=12, y=2 x=9, y=4 x=6, y=6 x=3, y=8 x=0, y=10 Notice the following: The value of x changes in increments of 3 (the coefficient for y). The value ...” May 28, 2019 Brent@GMATPrepNow posted a reply to Car X is 40 miles west of Car Y. Both cars are traveling in the Problem Solving forum “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 TOTAL distance traveled = ...” May 27, 2019 GMATGuruNY posted a reply to probability in the Problem Solving forum “3 wins and 2 losses = WWWLL. One way to determine the number of ways to get 3 wins is to count the number of ways to arrange the 5 letters WWWLL. The number of ways to arrange 5 elements = 5!. But when an arrangement includes IDENTICAL elements, we must divide by the number of ways each set of ...” May 27, 2019 GMATGuruNY posted a reply to in old problem.. in other point.. in the Sentence Correction forum “An ABSOLUTE PHRASE refers to the preceding subject. COMMA + APPOSITIVE serves to explain or define the nearest preceding noun or noun phrase. B and C: The computer company...will purchase the color-printing division of a rival company for$950 million, a part of a deal... Here, the modifier in ...”
May 27, 2019
Brent@GMATPrepNow posted a reply to Gita is 12 years older than Harvey. In 4 years, Gita will be in the Problem Solving forum
“Gita is 12 years older than Harvey. Let x = Harvey''s PRESENT age Let x + 12 = Gita''s PRESENT age In 4 years, . . . . x + 4 = Harvey''s age IN FOUR YEARS (x + 12) + 4 = Gita''s age IN FOUR YEARS . . . Gita will be twice as old as Harvey. So: (Gita''s age IN 4 YEARS) = 2(Harvey''s ...”
May 26, 2019
GMATGuruNY posted a reply to A bowl contains equal numbers of red, orange, green, blue, in the Problem Solving forum
“10 Let R=O=G=B=Y=20, for a total of 100 marbles. Kaz eats all of the green candies and half of the orange ones. R=20, O=10, G=0, B=20, Y=20 He eats half of the remaining pieces of each color. R=10, O=5, G=0, B=10, Y=10 He eats red and yellow candies in equal proportions until the total ...”
May 26, 2019
GMATGuruNY posted a reply to If a/b<c/d & bd < 0, which of the following inequa in the Problem Solving forum
“In I, II and III, test the following case: a=c=d=1 and b=-1, with the result that a/b < c/d and bd < 0. I: ad-bc < 0 Since ad=1*1=1 and bc=-1*1=-1, we get: 1 - (-1) < 0 2 < 0 Not true. Eliminate A and D, each of which include I. II: bc-ad > 0 Since bc=-1*1=-1 abd ...”
May 26, 2019
GMATGuruNY posted a reply to A husband and wife can complete a certain task in 1 and 2 in the Data Sufficiency forum
“Let the job = 12 units. Dividing the four given times into the 12-unit job, we get the following hourly rates: Husband:Wife:Rae:Herman = (12 per hour): (6 per hour) : (3 per hour) : (2 per hour) (Husband + Wife) : (Rae + Herman) = (12+6 per hour) : (3+2 per hour) Couple : Children = 18:5 ...”
May 24, 2019
Brent@GMATPrepNow posted a reply to Al and Ben are drivers for SD Trucking Company. One snowy da in the Problem Solving forum
“Let''s start with a "word equation" (Ben''s travel distance) + (Al''s travel distance) = 240 miles Let t = Al''s travel time (in hours) So, t + 3= Ben''s travel time (since Ben spent 3 more hours driving) Distance = (rate)(time) So, our word equation becomes... (20)(t + 3) = ...”
May 24, 2019
Brent@GMATPrepNow posted a reply to What is x in the diagram below? in the Problem Solving forum
“The important thing to recognize here is that there are two SIMILAR TRIANGLES hiding in this diagram. http://s24.postimg.cc/50bvp89dt/sim_tri.jpg Notice that these two triangles share both a 90-degree angle AND the angle I''ve denoted with a purple dot. Since the 3 angles in each triangle must ...”
May 24, 2019
Brent@GMATPrepNow posted a reply to j, k, m, x, y and z are positive integers. When j is divided in the Problem Solving forum
“Useful remainder property: When positive integer N is divided by positive integer D, the remainder R is such that 0 ≤ R < D For example, if we divide some positive integer by 7, the remainder will be 6, 5, 4, 3, 2, 1, or 0 When j is divided by k, the remainder is m The above property ...”
May 23, 2019
GMATGuruNY posted a reply to A jar contains 8 red marbles and $$y$$ white marbles. in the Data Sufficiency forum
“Test the THRESHOLDS and try EXTREMES. Here, the THRESHOLDS are y=8 and y=4. Statement 1: y≤8 Case 1: 8 white marbles, 8 red marbles P(RR) = 8/16 * 7/15 = 7/30. P(one of each color): P(RW) = 8/16 * 8/15 = 8/30. Since RW can be reversed to WR, we multiply by 2: 2(8/30) = 16/30. In ...”
May 23, 2019
GMATGuruNY posted a reply to Robots X, Y, and Z each assembled components at their in the Data Sufficiency forum
“Let X = X''s rate, Y = Y''s rate, and Z = Z''s rate. r(x) = the ratio of X''s rate to Z''s rate = X/Z. r(y) = the ratio of Y''s rate to Z''s rate = Y/Z. Note: X, Y and Z all represent rates and thus must be POSITIVE. Statement 1: r(x) < r(y) In other words: X/Z < Y/Z. Since ...”
May 23, 2019
GMATGuruNY posted a reply to In the diagram above, line BC touches the circle at point C in the Data Sufficiency forum
“To determine the area of the circle, we need to know its radius. Question stem, rephrased: What is the value of r? A radius drawn to a tangent line forms a RIGHT ANGLE. Thus, angle OCB is a right angle, with the result that triangle OCB is a right triangle. In right triangle OCB, OB=r, BC=35, ...”
May 23, 2019
GMATGuruNY posted a reply to NNN in the Critical Reasoning forum
“Consider the following case: The networks airs over one hundred programs focused largely on the opinions of its viewers. The NUMBER of programs tells us nothing about the NATURE of the opinions (whether they are liberal or conservative) or about the network''s REACTION to these opinions (whether ...”
May 23, 2019
Brent@GMATPrepNow posted a reply to Challenge question: Is positive integer p even? in the Data Sufficiency forum
“------ASIDE--------------------- Here''s a useful rule: 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 ...”
May 22, 2019
Brent@GMATPrepNow posted a new topic called j, k, m, x, y and z are positive integers. When j is divided in the Problem Solving forum
“j, k, m, x, y and z are positive integers. When j is divided by k, the remainder is m. When x is divided by y, the remainder is z. If ky = 75, which of the following CANNOT be the value of mz? i) 49 ii) 50 iii) 56 A) iii only B) i and ii C) i and iii D) ii and iii E) i, ii and iii ...”
May 22, 2019
Brent@GMATPrepNow posted a reply to If n is an integer greater than 6, which of the following in the Problem Solving forum
“One approach is to test values If n = 7, we get: (A) 7(7 + 1)(7 – 4) = (7)(8)(3). Definitely divisible by 3. KEEP (B) 7(7 + 2)(7 – 1) = (7)(9)(6). Definitely divisible by 3. KEEP (C) 7(7 + 3)(7 – 5) = (7)(10)(4). NOT divisible by 3. ELIMINATE. (D) 7(7 + 4)(7 – 2) = (7)(11)(5). NOT ...”
May 22, 2019
GMATGuruNY posted a reply to NNN in the Critical Reasoning forum
“The two statements together serve to form the conclusion of the programming director. A premise is a FACT not in dispute. A conclusion is an OPINION that CAN be disputed. Only one FACT is presented in the passage: When a liberal news personality was recently added to the Network, an additional ...”
May 22, 2019
GMATGuruNY posted a reply to A conveyor belt moves bottles at a constant speed of 120 in the Data Sufficiency forum
“Given rate: 120 centimeters per second. Since the statements are in terms of MINUTES, calculate the number of minutes required to move the bottle 90 meters: 90 meters * (100 centimeters)/(1 meter) * (1 second)/(120 centimeters) * (1 minute)/(60 seconds) = (90)/(12*6) = 15/12 = 5/4 = 1.25 minutes ...”
May 22, 2019
GMATGuruNY posted a reply to ps 500 test27 #16 in the Problem Solving forum
“John and Mary were each paid x dollars in advance to do a certain job together. John worked on the job for 10 hours. Mary worked 2 hours less than John. Since a total of 18 hours are worked -- 10 hours by John, 8 hours by Mary -- let x=18. Since John and Mary are each given $18 in advance, the ...” May 21, 2019 Brent@GMATPrepNow posted a reply to Question from mba.com mock test in the Problem Solving forum “The temperature of a certain cup of coffee 10 minutes after it was poured was 120 degrees Fahrenheit. So, 120 = 120 * 2^10)] + 60 Divide both sides by 60: 2 = 2 * 2^ f = 120 * 2^ The temperature of the coffee 30 minutes after it was poured was how many degrees Fahrenheit? f = 120 * 2^30)] + ...” May 21, 2019 Brent@GMATPrepNow posted a reply to OG #132 in the Problem Solving forum “We need to be able to create AT LEAST 12 codes (to represent the 12 countries). Let''s test the options. Can we get 12 or more color codes with 4 colors? Let''s see . . . 1-color codes = 4 (since there are 4 colors) 2-color codes = We need to choose 2 colors from 4. This can be ...” May 21, 2019 Brent@GMATPrepNow posted a reply to ps 500 test27 #16 in the Problem Solving forum “One approach: 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 ...” May 21, 2019 Brent@GMATPrepNow posted a reply to problem to solve in the Problem Solving forum “What we really have here is an algebra question requiring us to combine like terms. First, notice that K + K = 2K Using the same logic, 2^5 + 2^5 = 2(2^5) = (2^1)(2^5) = 2^6 Similarly, notice that M + M + M = 3M Using the same logic, 3^5 + 3^5 + 3^5 = 3(3^5) = (3^1)(3^5) = 3^6 So, 2^5 + ...” May 21, 2019 Brent@GMATPrepNow posted a reply to test 39 #13 in the Problem Solving forum “Here''s a related question to practice with: https://www.beatthegmat.com/intensity-scale-readings-t273997.html Cheers, Brent” May 21, 2019 Brent@GMATPrepNow posted a reply to test 38 #15 in the Problem Solving forum “red = 7 yellow = 5 green = 3 blue = 2 147,000 = (2)(2)(2)(3)(5)(5)(5)(7)(7) So, there are 3 blue beads, 1 green bead, 3 yellow beads and 2 red beads. Cheers, Brent” May 21, 2019 Brent@GMATPrepNow posted a reply to test35 # 15 in the Problem Solving forum “We want to determine how many integers end in 13 For example, 324713, 324813, 324913, 325013, . . . etc. Recognize that, for every 100 consecutive integers, only 1 will end in 13. There are 133,900 integers between 324,700 and 458,600 (since 458,600 - 324,700 = 133,900) Of those 133,900 ...” May 21, 2019 Brent@GMATPrepNow posted a reply to Help on PS problem- GMATprep in the Problem Solving forum “Let''s test the values using x = 0 So, we can reword the question as, For which of the following functions is f(0)=f(1-0) In other words, we''re looking for a function such that f(0) = f(1) A) f(x)=1-x f(0)=1-0 = 1 f(1)=1-1 = 0 Since f(0) doesn''t equal f(1), eliminate A B) f(x) = 1 - ...” May 21, 2019 Brent@GMATPrepNow posted a reply to Probability 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 ...” May 21, 2019 Brent@GMATPrepNow posted a reply to Mr. Jones spends$ 25 on movie tickets for a party of adults in the Data Sufficiency forum
“ Given: Mr. Jones spends $25 on movie tickets for a party of adults and children. Target question: How many children''s tickets did he buy? Statement 1: Adult movie tickets cost$3 each and children''s tickets cost $2 each. There are several scenarios that satisfy statement 1. Here are ...” May 21, 2019 Brent@GMATPrepNow posted a reply to A collection of 16 coins, each with a face value of either in the Problem Solving forum “Let D = the NUMBER of 10-cent coins Let Q = the NUMBER of 25-cent coins Notice that the VALUE of Q 25-cent coins = ($0.25)Q For example, the VALUE of six 25-cent coins = ($0.25)6 =$1.50 And the VALUE of ten 25-cent coins = ($0.25)10 =$2.50 etc Likewise, the VALUE of D 10-cent coins = ...”
May 21, 2019
Brent@GMATPrepNow posted a new topic called Challenge question: Is positive integer p even? in the Data Sufficiency forum
“Is positive integer p even? (1) 4p has twice as many positive divisors as p has (2) 8p has 3 positive divisors more than p has Answer: A Source: www.gmatprepnow.com Difficulty level: 700+”
May 20, 2019
GMATGuruNY posted a reply to Is x > 0? in the Data Sufficiency forum
“Note: |a|² = a² |a+b|² = (a+b)² Statement 1: Since an absolute value cannot be negative, both sides of the inequality must be nonnegative, allowing us to safely square it: (|x| + |y|)² > |x + y|² |x|² + |y|² + 2|x||y| > (x+y)² x² + y² + 2|x||y| > x² + y² + 2xy |x||y| ...”
May 20, 2019
GMATGuruNY posted a reply to If f(x)=x^4+4x^2+7, f(x)=g(x)^2+3 and g(x) > 0, then g(x) in the Problem Solving forum
“Let x=0, with the result that f(x) = 0+0+7 = 7. Remembering that g(x)>0 and plugging f(x)=7 into f(x)=g(x)²+3, we get: 7 = g(x)²+3 4 = g(x)² g(x) = 2 Since the question stem asks for the value of g(x), the correct answer must yield 2 when x=0. Only B works: x²+2 = 0²+2 = 2 The ...”
May 20, 2019
Brent@GMATPrepNow posted a reply to In the figure above, if A, B, and C are the areas, respectiv in the Data Sufficiency forum
“Key concept: We''re told that the area of the BLUE circle = the area of the RED circle https://i.imgur.com/AZaIFeU.png This means we can say: A + B = B + C Now onto the question..... Target question: What is the value of B + C ? Statement 1: A + 2B + C = 24 Rewrite this as: (A + B) ...”
May 17, 2019
GMATGuruNY posted a reply to (n+1)!f(n) = (n-1)!. What is the value of f(1) + f(2) + … in the Problem Solving forum
“f(n) = (n-1)!/(n+1)! f(1) = 0!/2! = 1/2 f(2) = 1!/3! = 1/6 f(3) = 2!/4! = 1/12 f(4) = 3!/5! = 1/20 f(1) + f(2) = 1/2 + 1/6 = 2/3 f(1) + f(2) + f(3) = 2/3 + 1/12 = 3/4 f(1) + f(2) + f(3) + f(4) = 3/4 + 1/20 = 4/5 The sum of the first 2 terms = 2/3. The sum of the first 3 terms = 3/4. ...”
May 17, 2019
GMATGuruNY posted a reply to A 3-digit positive integer consists of non zero digits. If in the Problem Solving forum
“Alternate approach: Integers with exactly 2 digits the same = Total integers - Integers with all 3 digits the same - Integers with all 3 digits different. Total integers: Number of options for the hundreds digit = 9. (Any digit but 0.) Number of options for the tens digit = 9. (Any digit ...”
May 16, 2019
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“Data Sufficiency lesson #7: - The Table Method Video : https://www.youtube.com/watch?v=lYfTiRIG_k4 Cheers, Brent”
May 16, 2019
GMATGuruNY posted a reply to What is the value of x? in the Data Sufficiency forum
“Statement 1: Squaring both sides, we get: x² + y² + 2xy = x² + y² - 2xy 4xy = 0 xy = 0 Case 1: x=0, with the result that y can be any value Case 2: y=0, with the result that x can be any value Since Case 2 allows x to be any value, INSUFFICIENT. Statement 2: Here, y can be any ...”
May 16, 2019
GMATGuruNY posted a reply to Each of A, B and C represents a one-digit integer. AB and BA in the Problem Solving forum
“325 = 100*3 + 10*2 + 5 648 = 100*6 + 10*4 + 8 Generally: Three-digit integer XYZ = 100X + 10Y + Z Since BA + AB + AB = CAA, we get: (10B+A) + (10A+B) + (10A+B) = 100C + 10A + A 12B + 21A = 100C + 11A 12B + 10A = 100C 12B + 10A = MULTIPLE OF 100 Since B and A are digits, the left side will ...”
May 16, 2019
GMATGuruNY posted a reply to The federal immigration station on Ellis Island - GMATPrep in the Sentence Correction forum
“Yes. E: Of all immigrants...the station processed nearly three quarters of them. Here, the red modifier is redundant with the blue modifier. Generally, COMMA + having + VERBed serves to express an action that happens before the action in the preceding clause. E: The federal immigration ...”
May 15, 2019
Brent@GMATPrepNow posted a reply to If Mary always takes the same route to work, how long did it in the Data Sufficiency forum
“Target question: How long did it take Mary to get to work on Friday? Statement 1: It took Mary 20 minutes to get to work on Thursday. Clearly, we cannot use this information to answer the target question with certainty. Statement 1 is NOT SUFFICIENT Statement 2: Mary''s average speed ...”
May 15, 2019
GMATGuruNY posted a reply to In the xy-coordinate system, rectangle ABCD is inscribed in the Problem Solving forum
“x²+y² = r² is the equation for a circle with its center at the origin and a radius of r. Thus, x²+y² = 25 is a circle with a center at the origin and a radius of 5. The information in the prompt yields the following figure: https://i.postimg.cc/xJCgjxbd/rectangle-in-circle.png OB is a ...”
May 15, 2019
Brent@GMATPrepNow posted a reply to x-4=z y-x=8 8-z=t For the system of equations given, what in the Data Sufficiency forum
“Target question: What is the value of z? Statement 1: x = 7 Scanning the three given equations, we see that equation i is all we need to determine the value of z i) x - 4 = z Replace x with 7 to get: 7 - 4 = z So, z = 3 Since we can answer the target question with certainty, statement 1 ...”
May 14, 2019
GMATGuruNY posted a reply to A retail store employs only clerks and managers and the in the Problem Solving forum
“Last year''s payroll = (number of employees)(average hourly wage) = 20*13 = 260. This year 4 clerks are hired, increasing the number of employees to 24. Since the average hourly wage this year = 14, we get: This year''s payroll = (number of employees)(average hourly wage) = 24*14 = 336. ...”
May 14, 2019
Brent@GMATPrepNow posted a reply to In triangle JKL shown above, what is the length of segment in the Data Sufficiency forum
“KEY CONCEPT: 30-60-90 triangles are known as special right triangles, and we know quite a bit about this kind of triangle Target question: What is the length of segment JL ? Statement 1: JK = 10 https://i.imgur.com/sKEFT1R.png Compare ΔJKL with the BASE 30-60-90 triangle. Their ...”
May 13, 2019
Brent@GMATPrepNow posted a reply to A line that passes through (–1, –4) and (3, k) has a slo in the Problem Solving forum
“Slope of line between the points (x1, y1) and (x2, y2) = (y2 - y1)/(x2 - x1) So, we can write: k = [k - (-4)]/[3 - (-1)] Simplify: (k + 4)/4 = k Multiply both sides by 4 to get: k + 4 = 4k Subtract k from both sides to get: 4 = 3k Divide both sides by 3 to get: 4/3 = k Answer: C Cheers, ...”
May 13, 2019
Brent@GMATPrepNow posted a reply to If the two digit integers M and N are positive and have the in the Problem Solving forum
“This question relies on our ability to determine the VALUE of any 2-digit number. For example, what is the VALUE of 83? For many of us, it has been a very long time since we examined this (we learned this when we were 5 or 6). Most of us just say that 83 has a value of 83, but 83 is really just ...”
May 13, 2019
GMATGuruNY posted a reply to According to public health officials in the Sentence Correction forum
“Incorrect: More babies were born in 1900 than they were born in 1800. Here, the usage of they implies that the SAME BABIES born in 1900 were also born in 1800 -- a nonsensical meaning. Generally: When a comparison begins with MORE/FEWER + SUBJECT + VERB, the implied clause after than should NOT ...”
May 13, 2019
GMATGuruNY posted a reply to An auto dealer sells each car at either $20,000 or$30,000. in the Data Sufficiency forum
“Statements combined: Case 1: 30 $30,000 cars are marked up 30%'' 20$20,000 cars are marked up 20% Case 2: 10 $30,000 cars are marked up 30% 20$20,000 cars are marked up 30% 20 $30,000 cars are marked up 20% In Case 1, the more expensive$30,000 cars are all sold at the higher profit ...”
May 13, 2019
Brent@GMATPrepNow posted a reply to If n is an integer greater than 10, then the expression (n^2 in the Problem Solving forum
“-----ASIDE--------------------- There''s a nice rule says: The product of k consecutive integers is divisible by k, k-1, k-2,...,2, and 1 So, for example, the product of any 5 consecutive integers will be divisible by 5, 4, 3, 2 and 1 Likewise, the product of any 11 consecutive integers will be ...”
May 12, 2019
GMATGuruNY posted a reply to OG 13 #9 in the Sentence Correction forum
“When a statistic decreases in value, we use lower rather than less. Incorrect: The temperature was less in the second experiment than in the first. Correct: The temperature was lower in the second experiment than in the first. Most of the country’s biggest daily newspapers had lower ...”
May 12, 2019
Brent@GMATPrepNow posted a reply to If x and y are the lengths of the legs of a right triangle, in the Data Sufficiency forum
“ Given: x and y are the lengths of the legs of a right triangle We have something like this: https://i.imgur.com/VxCexHO.png Target question: What is the value of xy? Statement 1: The hypotenuse of the triangle is There are infinitely-many different right triangles that meet this ...”
May 11, 2019
Brent@GMATPrepNow posted a reply to In how many different ways can a soccer team finish the in the Problem Solving forum
“Question rephrased: In how many different ways can we arrange the letters WWWLLD -------------ASIDE-------------------------------------- When we want to arrange a group of items in which some of the items are identical, we can use something called the If there are n objects where A of them are ...”
May 11, 2019
GMATGuruNY posted a reply to In how many different ways can a soccer team finish the in the Problem Solving forum
“Alternate approach: There are 6 slots in the season: 3 wins, 2 losses and 1 draw. From the 6 slots, the number of ways to choose 3 to be occupied by the 3 wins = 6C3 = (6*5*4)/(3*2*1) = 20. From the 3 remaining slots, the number of ways to choose 2 to be occupied by the 2 losses = 3C2 = ...”
May 11, 2019
GMATGuruNY posted a reply to OG 13 #9 in the Sentence Correction forum
“Here, greater serves to modify not costs but PROPORTION. Conveyed meaning: The PROPORTION in the presidential campaign of 1992 was greater than the PROPORTION in any previous election. When comparing elements with regard to WEIGHT, we generally use not lower but LESS. Adam weighs LESS than ...”
May 11, 2019
GMATGuruNY posted a reply to If a, b, and c are positive integers, what is the remainder in the Data Sufficiency forum
“Statement 1: No information about b. INSUFFICIENT. Statement 2: No information about a. INSUFFICIENT. Statements combined: Case 1: c=1, with the result that a=1³=1 and b=(1-2)³=-1 In this case, (a-b)/6 = C.”
May 11, 2019
GMATGuruNY posted a reply to If a, b, and c are positive integers, what is the remainder in the Data Sufficiency forum
“Statement 1: No information about b. INSUFFICIENT. Statement 2: No information about a. INSUFFICIENT. Statements combined: Case 1: c=1, with the result that a=1³=1 and b=(1-2)³=-1 In this case, (a-b)/6 = C.”
May 11, 2019
Brent@GMATPrepNow posted a reply to Jones has worked at Firm X twice as many years as Green in the Data Sufficiency forum
“We can also solve the question using one variable Given: Jones has worked at Firm X twice as many years as Green, and Green has worked at Firm X four years longer than Smith. Let G = the number of years Green worked at Firm X So, G - 4 = the number of years Smith worked at Firm X (since ...”
May 10, 2019
Brent@GMATPrepNow posted a reply to In the below addition A, B, C, D, E, F, and G represent the in the Problem Solving forum
“If we add two 2-digit numbers and the sum is a 3-digit number, then the 3-digit number must start with a 1. So, E = 1 In order for the sum to be a 3-digit number, A+C must be greater than 9 So, we have two options: EITHER A and C are 5 and 6, OR A and C are 4 and 6 If A and C are 5 and 6, ...”
May 10, 2019
GMATGuruNY posted a reply to According to surveys by the National Institute on Drug Abuse in the Sentence Correction forum
“Proposed revision: as many young adults as the 1997 survey reported Conveyed meaning: The 1997 survey reported many young adults. This meaning seems illogical. The 1997 survey reported a NUMBER. It did not report the young adults themselves.”
May 10, 2019
GMATGuruNY posted a reply to Ellipsis question in the Sentence Correction forum
“OA: Today, the same amount of acreage produces twice as many apples as it did in 1910. The phrase in blue conveys that the amount of acreage producing apples today is the SAME as the amount that produced apples in 1910. For example: If 100 acres produced apples in 1910, then 100 acres are ...”
May 10, 2019
GMATGuruNY posted a reply to An art gallery has only paintings and sculptures. Currently, in the Problem Solving forum
“This is an EITHER/OR group problem. Every piece of art is EITHER a painting OR a sculpture. Every piece of art is EITHER displayed OR not displayed. For an EITHER/OR group problem, we can use a GROUP GRID (also known as a double-matrix) to organize the data. Let P = paintings, S = ...”
May 10, 2019
Brent@GMATPrepNow posted a reply to If xyz ≠ 0, what is the value of in the Data Sufficiency forum
“Target question: What is the value of (x⁴z²)/(z²y²)? This is a good candidate for rephrasing the target question. Since z ≠ 0, we know that z² ≠ 0 So, we can safely take (x⁴z²)/(z²y²) and divide top and bottom by z² to get: x⁴/y² REPHRASED target question: What is the value ...”
May 9, 2019
Brent@GMATPrepNow posted a reply to Is quadrilateral PQRS a parallelogram? in the Data Sufficiency forum
“Target question: Is quadrilateral PQRS a parallelogram? If you recognize that each statement on its own is not sufficient, we can jump straight to . . . Statements 1 and 2 combined There are infinitely-many quadrilaterals that satisfy BOTH statements. Here are two: Case a: PQRS could ...”
May 9, 2019
Brent@GMATPrepNow posted a reply to A lecture course consists of 595 students. The students are in the Problem Solving forum
“In order to have an EQUAL number of students in each section, the number of students per section MUST BE A FACTOR of 595 Let''s do some prime factorization 595 = (5)(7)(17) From the prime factorization, we can see that answer choice A, B, D and E are all factors of 595 Answer: C Cheers, ...”
May 9, 2019
Brent@GMATPrepNow posted a reply to If a and b are constants, is the expression in the Data Sufficiency forum
“Target question: Is the expression defined for x = –2? This is a great candidate for rephrasing the target question. If x = -2, then the expression becomes (-2)+b/√(-2+a) There are two ways in which the expression(-2)+b/√(-2+a) is NOT defined: case i) If a = 2, then the fraction''s ...”
May 9, 2019
Brent@GMATPrepNow posted a reply to Is x = y? in the Data Sufficiency forum
“Target question: Is x = y? Statement 1: 2x/3 - y/3 = 1/3 Multiply both sides by 3 to get: 2x - y = 1 There are several values of x and y that satisfy this equation. Here are two: Case a: x = 1 and y = 1. In this case, the answer to the target question is YES, it is the case that x = y ...”
May 9, 2019
Brent@GMATPrepNow posted a reply to The figure above represents a box that has the shape of a in the Data Sufficiency forum
“Target question: What is the volume of the box? IMPORTANT: For geometry Data Sufficiency questions, we are typically checking to see whether the statements "lock" a particular angle, length, or shape into having just one possible measurement. This concept is discussed in much greater ...”
May 9, 2019
Brent@GMATPrepNow posted a reply to In the figure above, PQRT is a rectangle. What is the length in the Data Sufficiency forum
“Let''s assign some variables to some of the lengths... https://i.imgur.com/BpaiRKm.png Target question: What is the value of x? Statement 1: The area of region PQRS is 39 and TS = 6. Region PQRS is a TRAPEZOID Area of trapezoid = (height)(base1 + base2)/2 So, we get: (x)(y + z)/2 = 39 ...”
May 9, 2019
Brent@GMATPrepNow posted a reply to Charlie takes 2.5 hours to fly from Los Angeles to Mexico Ci in the Problem Solving forum
“Here''s how I would answer this in my head Average speed = total distance/total time = 1200/2.5 = 2400/5 = 4800/10 = 480 Answer: D Cheers, Brent”
May 9, 2019
GMATGuruNY posted a reply to The sum of two numbers is 1 and their product is -1. What is in the Problem Solving forum
“x³ + y³ = (x+y)(x²+y²-xy) Since x+y=1, we get: (x+y)² = 1² x² + y² + 2xy = 1 Substituting xy=-1 into x² + y² + 2xy = 1, we get: x² + y² + 2(-1) = 1 x² + y² = 3 Substituting x+y=1, x²+y²=3 and xy=-1 into x³ + y³ = (x+y)(x²+y²-xy), we get: x³ + y³ = (1)(3-(-1)) = ...”
May 8, 2019
Brent@GMATPrepNow posted a reply to What amount did Jean earn from the commission on her sales in the Data Sufficiency forum
“Target question: What amount did Jean earn from the commission on her sales in the FIRST HALF of 1988 ? Statement 1: In 1988 Jean''s commission was 5 percent of the total amount of her sales. We don''t know her total sales amount in 1988, AND we don''t know what happened in the FIRST HALF of ...”
May 8, 2019
GMATGuruNY posted a reply to According to surveys by the National Institute on Drug Abuse in the Sentence Correction forum
“Correct! The OA to SC71 in the OG11 includes a similar construction: The cameras of the Voyager II spacecraft detected six small, previously unseen moons circling Uranus, doubling...the number of satellites now known to orbit the distant planet.”
May 7, 2019
Brent@GMATPrepNow posted a reply to Six shipments of machine parts were shipped from a factory o in the Data Sufficiency forum
“We might be able to solve this one faster by first converting the fractions to decimals. S1=0.25 S2=0.2 S3=0.17 (approx) S4=0.15 S5=0.13 (approx) S6=0.1 Statement 1: S2 and S4 were shipped on the first truck. First truck has 0.2 + 0.15 = 0.35 Since the first truck holds more than 0.5, ...”
May 7, 2019
Brent@GMATPrepNow posted a reply to If a and b are integers, is a^5 < 4^b ? in the Data Sufficiency forum
“\ Target question: Is a^5 > 4^b Statement 1: a³ = -27 Solve to get: a = -3 So, a^5 = (-3)^5 = -243 Since 4^b will be POSITIVE for all values of b, the answer to the target question is NO, a^5 is definitely NOT greater than 4^b Since we can answer the target question with certainty, ...”
May 7, 2019
GMATGuruNY posted a reply to GMATPrep SC in the Sentence Correction forum
“Here, much and the increase are redundant, since both words refer to an amount. Proposed revision: The number of people flying first class on domestic flights rose sharply in 1990, twice the increase of the previous year. Implied comparison: The NUMBER OF PEOPLE flying in 1990 was twice ...”
May 7, 2019
Brent@GMATPrepNow posted a reply to Anthony and Michael sit on the six-member board of directors in the Problem Solving forum
“Let''s assume that we''re creating subcommittees. We want to place 6 people in the following spaces: _ _ _ | _ _ _ First, we place Michael in one subcommittee; it makes no difference which one: M _ _ | _ _ _ Now place Anthony. We can see that there are 5 spaces remaining. 2 spaces ...”
May 7, 2019
GMATGuruNY posted a reply to If each child in a group of children received either one or in the Data Sufficiency forum
“Let x = the number of children receiving 2 candies each and y = the number of children receiving 1 candy each. Thus: Total number of candies = 2x + y. Question stem, rephrased: What is the value of x? Statement 1: Of every 4 children, 1 receives 2 candies and 3 each receive 1 candy. ...”
May 7, 2019
GMATGuruNY posted a reply to Anthony and Michael sit on the six-member board of directors in the Problem Solving forum
“A 3-person committee that includes Michael will be composed of Michael and two other people chosen from the remaining five members. From 5 members, the number of ways to choose 2 = 5C2 = 10. Of these 10 pairs, the number that will include Anthony = 4. (Since there are 4 other people who could ...”
May 7, 2019
GMATGuruNY posted a reply to A bucket full worns in the Problem Solving forum
“Let the number of worms = 60. Since the rat eats 1/6 of the 60 worms -- in other words, 10 worms -- in 5 hours, the rat''s rate = w/t = 10/5 = 2 worms per hour. 1/4 of the 60 worms = 60/4 = 15 worms. Since the rat''s rate = 2 worms per hour, the time for the rat to eat 15 worms = w/r = 15/2 = 7.5 ...”
May 7, 2019
GMATGuruNY posted a reply to A book has 1000 pages numbered 1, 2, 3, …, and so on. How in the Problem Solving forum
“Ignore page 1000, since it does not include the digit 2. To make the calculation easier, consider the remaining pages numbered as 3-digit integers, beginning with 000 and ending with 999: 000, 001, 002...997, 998, 999 There are 1000 options between 000 to 999, inclusive. Since each option is ...”
May 7, 2019
Brent@GMATPrepNow posted a reply to If x is 8/3 percent of y, y is what percent of x? in the Problem Solving forum
“x percent = x/100 So, 8/3 percent = (8/3)/100 = (8/3)/(100/1) = (8/3)(1/100) = 8/300 GIVEN: x is 8/3 percent of y, We can write: x = 8/300 of y In other words: x = (8/300)(y) or......: x = 8y/300 y is what percent of x? Take: x = 8y/300 Multiply both sides by 300 to get: 300x = 8y ...”
May 7, 2019
GMATGuruNY posted a reply to The equation (M + 6)/36 = (p – 7)/21 relates two temperatu in the Problem Solving forum
“If M=30 and P=28, both sides of (M + 6)/36 = (P – 7)/21 are equal to 1. The correct answer must yield a valid equation for M=30 and P=28. When the question stem includes the phrase "which of the following," the correct answer is likely to be D or E. E: M = (12/7)P – 18 If M=30 ...”
May 6, 2019
GMATGuruNY posted a reply to What is the remainder when the product of the first 10 prime in the Problem Solving forum
“What is the remainder when 30 is divided by 4? One approach: 1. Break the dividend 30 into factors: 30 = 5*6 2. Divide the divisor 4 into each factor: 5/4 = 1 R1, 6/4 = 1 R2 3. Multiple the resulting remainders: 1*2 = 2 Step 3 indicates that 30 divided by 4 will yield a remainder of 2. ...”
May 6, 2019
GMATGuruNY posted a reply to If a jury of 12 people is to be selected randomly from a in the Problem Solving forum
“Question rephrased: What is the probability that at least 8 men will be selected to serve on the 12-member jury? P(good outcome) = 1 - P(bad outcome). Here, a BAD outcome means selecting a jury with FEWER than 8 men. Of the 10 men and 5 women in the jury pool, 3 people must be selected NOT ...”
May 5, 2019
Brent@GMATPrepNow posted a reply to Last year the range of the annual salaries of the 100 employ in the Problem Solving forum
“A quick solution is to assign some values to the highest paid and lowest paid workers Let $10,000 = the lowest salary LAST YEAR Let$40,000 = the highest salary LAST YEAR This satisfies the condition that the range LAST YEAR = $30,000 If the annual salary of each of the 100 employees this ...” May 4, 2019 Brent@GMATPrepNow posted a reply to Last year the range of the annual salaries of the 100 employ in the Problem Solving forum “Hey BTGmoderatorDC, You posted this question 2 months ago: https://www.beatthegmat.com/last-year-the-range-of-the-annual-salaries-of-the-100-t306593.html Cheers, Brent” May 4, 2019 Brent@GMATPrepNow posted a reply to A certain rectangular window is twice as long as it is wide. in the Problem Solving forum “Approach #2: Algebra Let x = the width of the rectangle So, 2x = the length of the rectangle If the perimeter is 10, we can write: x + x + 2x + 2x = 10 Simplify: 6x = 10 Solve: x = 10/6 = 5/3 So, the width (x) is 5/3 And the length (2x) is 10/3 Answer: B Cheers, Brent” May 4, 2019 Brent@GMATPrepNow posted a reply to A certain rectangular window is twice as long as it is wide. in the Problem Solving forum “We COULD use algebra to solve this question. However, it''s probably faster to just test the answer choices The answer choices give us the length and width of the rectangle. So, the sum of two values will equal HALF the perimeter of the rectangle. Since we want a perimeter of 10, the ...” May 4, 2019 Brent@GMATPrepNow posted a reply to Three-fourths of the area of a rectangular lawn 30 feet wide in the Problem Solving forum “Here''s a diagram of the 30 x 40 lawn https://i.imgur.com/6dQyyQ5.png If we keep the full width (of 30 feet), then the length of the enclosure = 3/4 of 40 = 30 feet https://i.imgur.com/nRkAVRU.png So, the enclosure is a 30 by 30 square. The PERIMETER = 30 + 30 + 30 + 30 = 120 feet If ...” May 4, 2019 Brent@GMATPrepNow posted a reply to If rectangle ABCD is inscribed in the circle above, what is in the Problem Solving forum “Draw a line connecting points A and C. https://i.imgur.com/fQaxM5q.png An important circle property (see video below for more info) tells us that, if we have a 90-degree inscribed angle, then that angle must be containing ("holding") the DIAMETER of the circle. So, we know that AC = ...” May 4, 2019 Brent@GMATPrepNow posted a reply to In quadrilateral ABCD above, what is the length of AB ? in the Problem Solving forum “https://i.imgur.com/srEvM6A.png If we focus on the blue right triangle, we can EITHER recognize that legs of length 3 and 4 are part of the 3-4-5 Pythagorean triplet, OR we can apply the Pythagorean Theorem. https://i.imgur.com/L50lEKr.png Either way, we''ll see that the triangle''s ...” May 4, 2019 GMATGuruNY posted a reply to 7, 9, 6, 4, 5, x If x is a number in the list above in the Data Sufficiency forum “Given numbers in ascending order: 4, 5, 6, 7, 9 Statement 1: Smallest 3 numbers are 4, 5, and 6. Greatest 3 numbers are 7, 9 and x, where x is any number greater than 7. Thus: Median = average of the 2 middle numbers =(6+7)/2 = 6.5. SUFFICIENT. Rule: For any set that is SYMMETRICAL ...” May 4, 2019 GMATGuruNY posted a reply to Romeo and Juliet play a dice game in which the two in the Problem Solving forum “Let P(R) = the probability that Romeo wins and P(J) = the probability that Juliet wins. Since there are only two possible outcomes -- either Romeo wins or Juliet wins -- we get: P(R) + P(J) = 1 Probability that Romeo wins on the first roll = 1/6 Probability that Romeo wins on the third roll ...” May 3, 2019 Brent@GMATPrepNow posted a reply to A paint mixture was formed by mixing exactly 3 colors of in the Data Sufficiency forum “Target question: How many gallons of green paint were used? Given: A paint mixture was formed by mixing exactly 3 colors of paint. By volume, the mixture was x% blue paint, y% green paint, and z% red paint. 1 gallon of blue paint and 3 gallons of red paint were used. In other words, we ...” May 2, 2019 Brent@GMATPrepNow posted a reply to If 2.00X and 3.00Y are 2 numbers in decimal form with thousa in the Data Sufficiency forum “ Given: 2.00X and 3.00Y are 2 numbers in decimal form with thousandths digits X and Y Target question: Is 3(2.00X) > 2(3.00Y)? This is a good candidate for rephrasing the target question. Since X is the thousandths digit, we can write: 2.00X = 2 + X/1000 Since Y is the thousandths ...” May 2, 2019 GMATGuruNY posted a reply to Tickets for all but 100 seats in a 10,000-seat stadium were in the Problem Solving forum “If all 10,000 tickets are sold, we get: 20% sold for$1 each = 2000*1 = 2,000 80% sold for $2 each = 8000*2 = 16,000 Total revenue = 2000+16000 = 18,000 Since 100 tickets are not actually sold, the total revenue must be a bit less than 18,000. The correct answer is B.” May 2, 2019 GMATGuruNY posted a reply to Tony owns six unique matched pairs of socks. All twelve sock in the Problem Solving forum “We can PLUG IN THE ANSWERS, which represent the minimum number of socks that must be pulled. When the correct answer choice is plugged in, the probability of NOT picking a matching pair will be LESS than 1/2 (implying that the probability of picking a matching pair will be MORE than 1/2). Since we ...” May 2, 2019 GMATGuruNY posted a reply to Tony owns six unique matched pairs of socks. All twelve sock in the Problem Solving forum “We can PLUG IN THE ANSWERS, which represent the minimum number of socks that must be pulled. When the correct answer choice is plugged in, the probability of NOT picking a matching pair will be LESS than 1/2 (implying that the probability of picking a matching pair will be MORE than 1/2). Since we ...” May 2, 2019 GMATGuruNY posted a reply to Train A leaves the station at 5:00, and travels north at 50 in the Data Sufficiency forum “Statement 1: From 5pm to 6pm, A travels on its own for 1 hour at a rate of 50 mph, with the result that A travels ahead 50 miles. Since B''s rate is unknown, we cannot determine when B catches up to A. INSUFFICIENT. Statement 2: Since A''s 50-mph rate is 5/6 of B''s rate, we get: 50 = ...” May 1, 2019 Brent@GMATPrepNow posted a reply to If n^m leaves a remainder of 1 after division by 7 for all in the Problem Solving forum “The most important piece of information is here: "for all positive integers n that are not multiples of 7" Since 2 is not a multiple of 7, then it must be the case that, for a particular value of m, 2^m leaves a remainder of 1 after division by 7 Let''s check the answer choices.... ...” May 1, 2019 GMATGuruNY posted a reply to x^2 + 4x + 1 = 0. What is the value of x^2 + 1/x^2? in the Problem Solving forum “x² + 4x + 1 = 0 Dividing both sides by x, we get: (x² + 4x + 1)/x = 0/x x + 4 + 1/x = 0 x + 1/x = -4 Squaring both sides, we get: (x + 1/x)² = (-4)² x² + 1/x² + 2(x)(1/x) = 16 x² + 1/x² + 2 = 16 x² + 1/x² = 14 The correct answer is C.” May 1, 2019 Brent@GMATPrepNow posted a reply to If x is an integer greater than 0, what is the remainder in the Data Sufficiency forum “Target question: What is the remainder when x is divided by 4 ? Statement 1: The remainder is 3 when x + 1 is divided by 4. ------ASIDE---------------------- There''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 ...” May 1, 2019 Brent@GMATPrepNow posted a reply to What number is 6 more than x + y ? in the Data Sufficiency forum “Target question: What is the value of x + y + 6? Statement 1: y is 3 less than x. We can write: y = x - 3 There are several values of x and y that satisfy this equation. Here are two: Case a: x = 3 and y = 0. In this case, the answer to the target question is x + y + 6 = 3 + 0 + 6 = 9 ...” May 1, 2019 Brent@GMATPrepNow posted a reply to Is the average (arithmetic mean) of the numbers x, y, and z in the Data Sufficiency forum “Target question: Is the average (arithmetic mean) of the numbers x, y, and z greater than z? This is a good candidate for rephrasing the target question. Rewrite the question as "Is (x + y + z)/3 > z?" Multiply both sides by 3 to get: "Is x + y + z > 3z?" Subtract z ...” May 1, 2019 Brent@GMATPrepNow posted a reply to Every object in a box is either a sphere or a cube, and ever in the Data Sufficiency forum “Target question: How many objects are in the box? Given: Every object in a box is either a sphere or a cube, and every object in the box is either red or green. We can solve this using the Double Matrix Method. This technique can be used for most questions featuring a population in which ...” May 1, 2019 Brent@GMATPrepNow posted a reply to What is the remainder when the positive integer n is divided in the Data Sufficiency forum “Target question: What is the remainder when the positive integer n is divided by 5 ? Statement 1: When n is divided by 3, the quotient is 4 and the remainder is 1. There''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 ...” April 30, 2019 Brent@GMATPrepNow posted a reply to Is n equal to zero? in the Data Sufficiency forum “Target question: Is n equal to zero? Statement 1: The product of n and some nonzero number is 0 (n)(non-zero number) = 0 This means n must be 0 Since we can answer the target question with certainty, statement 1 is SUFFICIENT Statement 2: The sum of n and 0 is 0 If n + 0 = 0, we can ...” April 30, 2019 Brent@GMATPrepNow posted a reply to If r and s are positive numbers and θ is one in the Data Sufficiency forum “ Given: r and s are positive numbers and θ is one of the operations, +, −, ×, or ÷ Target question: Which operation is θ ? Statement 1: If r = s, then r θ s = 0 Keep in mind that r and s are POSITIVE So, we have POSITIVE θ POSITIVE = 0 POSITIVE + POSITIVE ≠ 0 So, θ cannot ...” April 30, 2019 Brent@GMATPrepNow posted a reply to How many hours does it take Jennifer to run y miles if she r in the Problem Solving forum “time = distance/rate So, time = y/x Answer: B Cheers, Brent” April 30, 2019 Brent@GMATPrepNow posted a reply to If x = 5 – 4k and y = 5k – 3, then for what value of k d in the Problem Solving forum “We want: x = y Replace values with their equivalents: 5 - 4k = 5k - 3 Add 4k to both sides: 5 = 9k - 3 Add 3 to both sides: 8 = 9k Divide both sides by 9 to get: 8/9 = k Answer: B Cheers, Brent” April 30, 2019 GMATGuruNY posted a reply to For all his professed disdain of such activities, Auden was in the Sentence Correction forum “When a sentence begins with for all + POSSESSIVE, for all = DESPITE. OA: For all his professed disdain of such activities, Auden was an inveterate literary gossip. Conveyed meaning: Despite his professed disdain of such activities, Auden was an inveterate literary gossip. E: In spite of ...” April 30, 2019 GMATGuruNY posted a reply to Is x+y>0? in the Data Sufficiency forum “Statement 1: Here, x and y must have the SAME SIGN. If x and y are both positive, then x+y > 0. If x and y are both negative, then x+y < 0. INSUFFICIENT. Statement 2: The inequality implies that x and y are both NONZERO. Since the square of a nonzero value must be positive, we can ...” April 30, 2019 GMATGuruNY posted a reply to Last year, the average price of eight different products in the Data Sufficiency forum “We can determine this year''s average price if we know the difference between this year''s revenue and last year''s. Statements combined: Case 1: Last year the 5 products in Statement 1 had an average price of$10, for a total of $50 in revenue In this case, the increase in revenue yielded by ...” April 30, 2019 GMATGuruNY posted a reply to A basketball coach has won 65 percent of the 400 games she in the Problem Solving forum “Total games = (400 games already played) + (100 additional games) = 500. Required number of wins = 70% of 500 = 350. Current number of wins = 65% of 400 = 260. Additional wins needed = 350-260 = 90. The correct answer is D.” April 30, 2019 GMATGuruNY posted a reply to What is the remainder when 1044*1047*1050*1053 is in the Problem Solving forum “What is the remainder when 30 is divided by 4? One approach: 1. Break the dividend 30 into factors: 30 = 5*6 2. Divide the divisor 4 into each factor: 5/4 = 1 R1, 6/4 = 1 R2 3. Multiple the resulting remainders: 1*2 = 2 Step 3 indicates that 30 divided by 4 will yield a remainder of 2. ...” April 30, 2019 Brent@GMATPrepNow posted a reply to If a school district paid a total of$35 per desk for x desk in the Data Sufficiency forum
“ Given: School district paid a total of $35 per desk for x desks and a total of$30 per table for y tables So, the TOTAL amount paid = 35x + 30y. Target question: What was the total amount that the district paid for these desks and tables?? Statement 1: The total amount the district ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to In a sequence of numbers in which each term is 2 more than in the Data Sufficiency forum
“ Given: Sequence of numbers is such that each term is 2 more than the preceding term Target question: What is the value of term_4? Statement 1: The last term is 90. We have no idea how many terms there are in the sequence. So, the last term could be term_5 or term_9 or term_12 or . . . ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to Is the integer p divisible by 5 ? in the Data Sufficiency forum
“Target question: Is the integer p divisible by 5? Statement 1: p is divisible by 10. If p is divisible by 10, we can write: p = 10k, for some integer k. Rewrite this as: p = (5)(2)(k) This tells us that p is a multiple of 5, which means p must be divisible by 5 Since we can answer the ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to If R, S, and T are points on a line in the Data Sufficiency forum
“ Given: R, S, and T are points on a line, and if R is 5 meters from T and 2 meters from S There are 4 possible scenarios that meet the above conditions: https://i.imgur.com/kOeqUfZ.png Target question: How far is S from T? Statement 1: R is between S and T. When we check the 4 ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to If m and n are integers, what is the value of m + n ? in the Data Sufficiency forum
“ Given: m and n are integers Target question: What is the value of m + n ? Statement 1: (x + m)(x + n) = x² + 5x + mn and x ≠ 0. Use FOIL to expand the left side: x² + nx + mx + mn = x² + 5x + mn Factor the two middle terms: x² + x(n + m) + mn = x² + 5x + mn At this point, we ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to If a and b are integers, and b > 0, does (a−1)/(b+1) = in the Data Sufficiency forum
“ Given: a and b are integers, and b > 0 Target question: Does (a - 1)/(b + 1) = a/b? This is a good candidate for rephrasing the target question. Take the equation: (a - 1)/(b + 1) = a/b Cross multiply to get: (b)(a - 1) = (a)(b + 1) Expand both sides to get: ab - b = ab + a ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to Is the sum of two integers divisible by 10 ? in the Data Sufficiency forum
“Target question: Is the sum of two integers divisible by 10 ? Statement 1: One of the integers is even. We only have information about ONE number. Statement 1 is NOT SUFFICIENT Statement 2: One of the integers is a multiple of 5. We only have information about ONE number. Statement 2 ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to If p, r, and s are consecutive integers in ascending in the Data Sufficiency forum
“ Given: p, r, and s are consecutive integers in ascending order and x is the average (arithmetic mean) of the three integers Since p, r and s are EQUALLY spaced, the mean of the 3 numbers = the median of the 3 numbers. Since p < r < s, we know that r = the mean = the median. In other ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to Three children inherited a total of X dollars. If the oldest in the Data Sufficiency forum
“ Given: Three children inherited a total of X dollars. The oldest child inherited $7,000 more than the youngest child, and the youngest child inherited$9,000 less than the middle child Let y = the amount the YOUNGEST child received So, y + 7000 = the amount the OLDEST child received And y + ...”
April 29, 2019
Brent@GMATPrepNow posted a reply to Is x<y? in the Data Sufficiency forum
“Target question: Is x < y? Statement 1: z< y No information about x Statement 1 is NOT SUFFICIENT Statement 2: z < x No information about y Statement 2 is NOT SUFFICIENT Statements 1 and 2 combined The combined statements tell us that x and y are both greater than z ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to What is the value of a^4 - b^4? in the Data Sufficiency forum
“Target question: What is the value of a⁴ - b⁴? NOTE: a⁴ - b⁴ is a difference of square, which we can factor. a⁴ - b⁴ = (a² - b²)(a² + b²) So, we can REPHRASE the target question as... REPHRASED target question: What is the value of (a² - b²)(a² + b²)? Statement 1: ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to Which of the following could be the equation of line m? in the Problem Solving forum
“First off, we can eliminate answer choice D, since y = 2 is the equation of a HORIZONTAL line, and the given line is NOT horizontal. Next, we can eliminate answer choice E, since x = -2 is the equation of a VERTICAL line, and the given line is NOT vertical. Now notice that line m has a ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to If S is a set of odd integers and 3 and -1... in the Data Sufficiency forum
“ Given: S is a set of odd integers and 3 and –1 are in S Target question: Is –15 in S ? Statement 1: 5 is in S So far, set S looks like this: {-1, 3, 5, . . . .} So, -15 may or may not be in set S Since we cannot answer the target question with certainty, statement 1 is NOT ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to If r and s are positive integers... in the Data Sufficiency forum
“ Given: r and s are positive integers Target question: Is r + s even? Statement 1: r is even. Since we have no information about s, we cannot determine whether r + s is even Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT Statement 2: s is ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to When positive integer k is divided by 5, the remainder is 2. in the Problem Solving 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), ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to Is the integer x a 3-digit integer? in the Data Sufficiency forum
“Target question: Is the integer x a 3-digit integer? Statement 1: x is the square of an integer. Let''s TEST some values. There are several values of x that satisfy statement 1. Here are two: Case a: x = 10² = 100. In this case, the answer to the target question is YES, x IS a 3-digit ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to If the 1st term of a sequence is 0 and the 2nd term is 1... in the Data Sufficiency forum
“ Given: term1 = 0 and term2 = 1 Target question: Does term5 equal 2? Once we scan the two statements, we can probably jump straight to . . . Statements 1 and 2 combined There are several possible sequences that satisfy BOTH statements. Here are two: Case a: {0, 1, 2, 0, 2,...}. In ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to Is the sum of four particular integers even? in the Data Sufficiency forum
“Some important rules: #1. ODD +/- ODD = EVEN #2. ODD +/- EVEN = ODD #3. EVEN +/- EVEN = EVEN #4. (ODD)(ODD) = ODD #5. (ODD)(EVEN) = EVEN #6. (EVEN)(EVEN) = EVEN Target question: Is the sum of four particular integers even? Statement 1: Two of the integers are odd and two are even. ...”
April 28, 2019
GMATGuruNY posted a reply to What is the units digit of the number z? in the Data Sufficiency forum
“Statements combined: Case 1: z=19, with the result that z is between both 17 and 20 and 18 and 21 In this case, the units digit of z is 9. Case 2: z=18.1, with the result that z is between both 17 and 20 and 18 and 21 In this case, the units digit of z is 8. Since the units digit can be ...”
April 28, 2019
GMATGuruNY posted a reply to The number line shown contains three points R, S, and T in the Problem Solving forum
“Let R=-3, S=3 and T=6, implying that r=|-3|=3, s=|3|=3, and t=|6|=6. Average of R, S, and T = (-3+3+6)/3 = 2. The correct answer must yield 2 when r=3, s=3 and t=6. Only E works: (s + t - r)/3 = (3+6-3)/3 = 6/3 = 2 The correct answer is E.”
April 28, 2019
GMATGuruNY posted a reply to Peter and Tom shared the driving on a certain trip. in the Problem Solving forum
“Let the total distance = 5 miles and the time for each driver = 1 hour. Since Peter drives 2/5 of the total distance -- 2 miles -- in 1 hour, Peter''s speed = d/t = 2/1 = 2 miles per hour. Since Tom drives the remaining distance -- 3 miles -- in 1 hour, Tom''s speed = d/t = 3/1 = 3 miles per ...”
April 28, 2019
Brent@GMATPrepNow posted a reply to If 90/k is an integer, is k an integer? in the Data Sufficiency forum
“ Given: 90/k is an integer Target question: Is k an integer? Statement 1: k > 1 Let''s TEST some values. There are several values of k that satisfy statement 1. Here are two: Case a: k = 10. Notice that 90/k = 90/10 = 9, which is an integer. In this case, the answer to the target ...”
April 27, 2019
Brent@GMATPrepNow posted a reply to For a recent play performance, the ticket prices were $25 in the Data Sufficiency forum “Target question: How many of the tickets sold were for adults? Given: A total of 500 tickets were sold for the performance Let C = # of child tickets sold Let A = # of adult tickets sold So, C + A = 500 Statement 1: Revenue from ticket sales for this performance totaled$10,500 In other ...”
April 27, 2019
Brent@GMATPrepNow posted a reply to The arithmetic mean of a data set is 46 and the standard in the Problem Solving forum
“-----------ASIDE----------------- A little extra background on standard deviations above and below the mean If, for example, a set has a standard deviation of 4, then: 1 standard deviation = 4 2 standard deviations = 8 3 standard deviations = 12 1.5 standard deviations = 6 0.25 ...”
April 27, 2019
Brent@GMATPrepNow posted a reply to In the town of Z, the town lion roars on some days and not in the Data Sufficiency forum
“Target question: What is the probability that on that day, either the town lion roared or it rained? This is a good candidate for rephrasing the target question. This is an OR probability. The OR probability rule says, P(A or B) = P(A) + P(B) - P(A and B) So, P(rained or roared) = P(rained) + ...”
April 27, 2019
Brent@GMATPrepNow posted a reply to If 20 percent of x is 5y, and y = 7, what is 60 percent in the Problem Solving forum
“GIVEN: 20 percent of x = 5y This means: 40 percent of x = 10y And: 60 percent of x = 15y Since y = 7, we can write: 60 percent of x = 15(7) = 105 Answer: A”
April 27, 2019
Brent@GMATPrepNow posted a reply to Is x^2 > 15? in the Data Sufficiency forum
“Target question: Is x² > 15? Statement 1: x > -4 Let''s TEST some values. There are several values of x that satisfy statement 1. Here are two: Case a: x = -1. In this case, x² = (-1)² = 1. So, the answer to the target question is NO, x² is NOT greater than 15 Case b: x = ...”
April 27, 2019
GMATGuruNY posted a reply to Ten theater students are to begin work on a set for a musica in the Problem Solving forum
“(50 days)/(60 days) = 5/6. To finish the job in 5/6 of the normal time, the crew requires 6/5 of the normal number of students -- an increase of 1/5: (1/5)(10) = 2 more students. The correct answer is A.”
April 27, 2019
Brent@GMATPrepNow posted a reply to If digit $$h$$ is the hudredths' digit in the decimal in the Data Sufficiency forum
“ Given: Digit h is the hundredths digit in the decimal d=0.2h6 Target question: What is the value of d, rounded to the nearest TENTH? Statement 1: d < 1/4 In other words, 0.2h6 < 0.25 This means h = 0, 1, 2, 3 or 4 If h = 0, 1, 2, 3 or 4, then 0.2h6 (aka d) rounded to the nearest ...”
April 26, 2019
Brent@GMATPrepNow posted a reply to In the rectangular coordinate system, line $$k$$ is defined in the Data Sufficiency forum
“KEY CONCEPT: If a point lies ON a line, then the coordinates (x and y) of that point must SATISFY the equation of the line. Given: Line k is defined by the equation x - 2y + n = 0 Target question: What is the value of n? Statement 1: The x-intercept of line k is 8 In other words, ...”
April 26, 2019
GMATGuruNY posted a reply to OG Most of the country's biggest daily newspapers in the Sentence Correction forum
“Plural terms such as profits, revenues, costs, etc. refer to NUMERICAL VALUES. When comparing plural terms that refer to numerical values, we generally do not use more but instead use -ER comparatives such as higher, lower, greater, etc. Thus, the blue sentence above is correct; the red sentence ...”
April 26, 2019
Brent@GMATPrepNow posted a reply to If z is a three-digit positive integer, what is the value in the Data Sufficiency forum
“ Given: z is a three-digit positive integer Target question: What is the value of the tens digit of z ? Statement 1: The tens digit of z - 91 is 3 Let''s examine two EXTREME cases z - 91 = 30 z - 91 = 39 NOTE: These are extreme cases, because 30 is the smallest 2-digit number ...”
April 25, 2019
Brent@GMATPrepNow posted a reply to Of the 60 animals on a certain farm, 2/3 are either pigs or in the Data Sufficiency forum
“Target question: How many of the animals are cows? Given: Of the 60 animals in a certain farm, 2/3 are either pigs or cows Let P = # of pigs Let C = # of cows 2/3 of 60 = 40, so we can say that P + C = 40 Statement 1: The farm has MORE THAN twice as many cows as it has pigs. In other ...”
April 25, 2019
GMATGuruNY posted a reply to Suppose x = a/b (b≠0). Which of following is equivalent to in the Problem Solving forum
“Let a=2 and b=1, with the result that x = a/b = 2/1 = 2 and that (a²+ab)/(a²+b²) = (4+2)/(4+1) = 6/5. The correct answer must yield 6/5 when x=2. Only A works: (x²+x)/(x²+1) = (4+2)/(4+1) = 6/5 The correct answer is A.”
April 25, 2019
GMATGuruNY posted a reply to Probability Question in the Problem Solving forum
“The approach above counts the following: Cases that include 11: 1122, 1133, 1144, 1155, 1166 Cases that include 22: 2211, 2233, 2244, 2255, 2266 Cases that include 33: 3311, 3322, 3344, 3355, 3366 Cases that include 44: 4411, 4422, 4433, 4455, 4466 Cases that include 55: 5511, 5522, ...”
April 25, 2019
GMATGuruNY posted a reply to On account of a law in the Sentence Correction forum
“The OA is correct because it contains no grammatical errors and conveys a logical meaning. OA: With the cost of wireless service plummeting, many people are now using their mobile phones. Here, the action in blue is accompanied by the plummeting cost of wireless service. This meaning is perfectly ...”
April 24, 2019
Brent@GMATPrepNow posted a reply to Bill rides his bike to work in the morning on a route that in the Data Sufficiency forum
“Here''s a similar question to practice with: https://www.beatthegmat.com/distance-t273181.html Cheers, Brent”
April 24, 2019
Brent@GMATPrepNow posted a reply to What is the value of x? in the Data Sufficiency forum
“Target question: What is the value of x? Statement 1: 4x = 2y − 6 Divide both sides by 2 to get: 2x = y - 3 Divide both sides by 2 (again) to get: x = (y - 3)/2 As you might guess, there are infinitely many solutions to the equation x = (y - 3)/2. Here are two: Case a: y = 3, and x = 0. ...”
April 24, 2019
Brent@GMATPrepNow posted a reply to Phone plan A charges $1.25 for the first minute and$0.15 in the Problem Solving forum
“Phone plan A charges $1.25 for the first minute and$0.15 for every minute thereafter. Let x = total duration of phone call (in minutes) So, the cost of an x-minute call = $1.25 + ($0.15)(x - 1) ASIDE: I created the expression ($0.15)(x - 1) because we pay$1.25 for the FIRST minute. So, if x = ...”
April 24, 2019
Brent@GMATPrepNow posted a reply to A piece of twine of length t is cut into two pieces. in the Problem Solving forum
“A piece of twine of length t is cut into two pieces. Let x = the length of the LONGER piece in yards So, t - x = the length of the SHORTER piece in yards The length of the longer piece is 2 yards greater than 3 times the length of the shorter piece. In other words: (longer piece) = ...”
April 22, 2019
Brent@GMATPrepNow posted a reply to √(16∗20+8∗32)= in the Problem Solving forum
“One option here is to evaluate (16)(20)+(8)(32), and then find the square root of the result. That''s a bit of work. We can also apply a technique called "Multiplying by Doubling and Halving" (here''s the video: I factored out the 16 = √sqrt(xy) = (√x)(√y)] √[(16)(36)] = ...”
April 22, 2019
GMATGuruNY posted a reply to Probability Question in the Problem Solving forum
“All possible rolls: Since there are 6 number options for each roll, we get: 6*6*6*6 = 1296 Case 1: Exactly 2 rolls are the same (such as 1123) From 4 rolls, the number of ways to choose a pair to yield the same number = 4C2 = (4*3)/(2*1) = 6. Number options for this pair = 6. (Any of the 6 ...”
April 22, 2019
Brent@GMATPrepNow posted a reply to Sequence $$X$$ consists of $$825$$ terms, and each term in the Data Sufficiency forum
“Target question: What is the value of term 500? Given: Each term after the first term is 5 more than the preceding term. Statement 1: Term 515 of sequence X is -98. Since each term is 5 more than the preceding term, we know that term 514 = -103 term 513 = -108 term 512 = -113 term ...”
April 21, 2019
Brent@GMATPrepNow posted a reply to From a group of 5 managers (Joon, Kendra, Lee, Marnie and in the Problem Solving forum
“Our goal is to find P(M and N both selected) Method #1: P(M and N both selected) = P(one of them is selected 1st AND the other selected 2nd) = P(one of them is selected 1st) x P(the other selected 2nd) = (2/5)(1/4) = 1/10 = 0.1 Aside: P(one of them is selected 1st) = 2/5 because I''m ...”
April 21, 2019
GMATGuruNY posted a reply to If j > 1, is integer j a prime number? in the Data Sufficiency forum
“Statements combined: Since dividing by 3 or 2 leaves a remainder of 1, j must be 1 more than a multiple of 3 and 2: j = (3*2)a + 1 = 6a + 1, where a is a positive integer Options for j: 7, 13, 19, 25... If j=7, then the answer to the question stem is YES. If j=25, then the answer to the ...”
April 21, 2019
GMATGuruNY posted a reply to From a group of 5 managers (Joon, Kendra, Lee, Marnie and in the Problem Solving forum
“Approach 1; P = (good pair)/(all possible pairs) Good pair = Marnie and Noomi = 1 option. All possible pairs = the number of ways to select 2 managers from 5 options = 5C2 = (5*4)/(2*1) = 10 options. Thus: P = 1/10 = 0.1 Approach 2: P(M or N is selected first) = 2/5. (Of the 5 managers, 2 ...”
April 21, 2019
Brent@GMATPrepNow posted a reply to What is the perimeter of quadrilateral Q? in the Data Sufficiency forum
“Target question: What is the perimeter of quadrilateral Q? If we recognize that each statement alone is not sufficient, we can jump straight to...... Statements 1 and 2 combined There are several quadrilaterals satisfy BOTH statements. Here are two: Case a: Q is a rectangle with width 1 ...”
April 20, 2019
Brent@GMATPrepNow posted a reply to Mary's income is 60 percent more than Tim's income, and in the Problem Solving forum
“I suggest that we choose some nice values that meet the given conditions. Tim''s income is 40 percent less than Juan''s income. Let Juan''s income = $100 40% of$100 = $40 This means Tim''s income =$100 - $40 =$60 Mary''s income is 60 percent more than Tim''s income 60% of $60 =$36 So ...”
April 20, 2019
Brent@GMATPrepNow posted a reply to For integers x and y, when x is divided by y, the remainder in the Problem Solving forum
“Since, the question asks "Which of the following must be true?", we can eliminate any answer choice that is not necessarily true. So let''s test some values that satisfy the given conditions For integers x and y, when x is divided by y, the remainder is odd. One possible case is that ...”
April 20, 2019
Brent@GMATPrepNow posted a reply to A certain library assesses fines for overdue books as follow 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 20, 2019 Brent@GMATPrepNow posted a reply to For the 5 days shown in the graph, how many kilowatt-hours in the Problem Solving forum “List the numbers in ASCENDING ORDER to get: 19, 24, 27, 29, 31. So 27 is the median. Average = (19 + 24 + 27 + 29 + 31)/5 = 130/5 = 26. The median (27) is 1 greater than the average (26). Answer: A Cheers, Brent” April 20, 2019 GMATGuruNY posted a reply to While it costs about the same in the Sentence Correction forum “Here, the phrase in blue implies that people were trying to drive on the freeway but that the process was made challenging by the rain. This meaning is logical. Here, the phrase in red implies that nuclear plants are trying to generate electricity but that the process is made more expensive ...” April 20, 2019 GMATGuruNY posted a reply to Discussion of greenhouse effects has usually in the Sentence Correction forum “An effect is a CHANGE brought about by an event. The Earth ALWAYS has a temperature. Since temperature does not constitute a change, it cannot be an effect. In the OA, EXTREMES are the change brought about by greenhouse emissions. This meaning is logical. The temperature of the Earth is not ...” April 20, 2019 GMATGuruNY posted a reply to What is the value of |x|? in the Data Sufficiency forum “Statement 1: Case 1: x=0, with the result that -|x| = - |0| = 0 In this case, |x| = 0. Case 2: x=-1, with the result that -|-1| = -1 In this case, |x| = 1. Since |x| can be different values, INSUFFICIENT. Statement 2: Thus, x=2 or x=-2. In each case, |x|=2. SUFFICIENT. The correct ...” April 20, 2019 GMATGuruNY posted a reply to Mary's income is 60 percent more than Tim's income, and in the Problem Solving forum “Let J=100. Since Tim''s income is 40% less than Juan''s, T = 100 - (40% of 100) = 100 - 40 = 60. Since Mary''s income is 60% greater than Tim''s, M = 60 + (60% of 60) = 60 + 36 = 96. What percent of Juan''s income is Mary''s income? M/J = 96/100 = 96%. The correct answer is C.” April 20, 2019 Brent@GMATPrepNow posted a reply to What are the coordinates of point B in the figure above? in the Data Sufficiency forum “IMPORTANT: For geometry Data Sufficiency questions, we are typically checking to see whether the statements "lock" a particular angle, length, or shape into having just one possible measurement. This concept is discussed in much greater detail in the video below. Target question: What ...” April 19, 2019 Brent@GMATPrepNow posted a reply to If (x # y) represents the remainder that results when the in the Problem Solving forum “If y > 16, (16 # y) = 16, so we need only check the values from 1 to 15 Also, we need not check the FACTORS of 16, since they will all yield a remainder of 0 We''re left with: (16 # 3) = 1 KEEP! (16 # 5) = 1 KEEP (16 # 7) = 2 (16 # 9) = 7 (16 # 10) = 6 (16 # 11) = 5 (16 # 12) = 4 (16 # ...” April 19, 2019 Brent@GMATPrepNow posted a reply to If x and y are positive integers, is x^2*y^2 even ? in the Data Sufficiency forum “Target question: Is x²y² even ? Statement 1: x + 5 is a prime number So, x+5 is a prime number greater than 5, which means x+5 must be ODD (since 2 is only even prime) If x+5 is ODD, then x must be EVEN If x is EVEN, then x²y² must be even The answer to the target question is YES, ...” April 19, 2019 Brent@GMATPrepNow posted a reply to The areas of three faces of a rectangular solid are 12, 15 a in the Problem Solving forum “Let x = the width Let y = the length Let z = the height So, the volume = xyz Area of one face = 12 We can write: xy = 12 Area of one face = 15 We can write: xz = 15 Area of one face = 20 We can write: yz = 20 Combine to get: (xy)(xz)(yz) = (12)(15)(20) Simplify: x²y²z² = 3600 ...” April 19, 2019 Brent@GMATPrepNow posted a reply to OG 2019 related questions for daily emails in the The 60-Day GMAT Study Guide forum “The OGs vary by very little with each edition. So, you can just use an earlier edition (see https://www.beatthegmat.com/official-guide-question-library-t296759.html) Cheers, Brent” April 18, 2019 Brent@GMATPrepNow posted a reply to OG 2019 related questions for daily emails in the The 60-Day GMAT Study Guide forum “Sorry, but there are no plans to update BTG''s 60-Day Study Guide to include OG2019 questions.” April 18, 2019 Brent@GMATPrepNow posted a reply to If f(2x - 1) = 4x² - 4x - 8, then f(5) = in the Problem Solving forum “Here''s one more approach: First notice that 4x² - 4x - 8 looks a lot like (2x - 1)² (2x - 1)² = (2x - 1)(2x - 1) = 4x² - 4x + 1 Now take: f(2x - 1) = 4x² - 4x - 8 Rewrite as: f(2x - 1) = 4x² - 4x + 1 - 9 = (2x - 1)² - 9 In other words, f(something) =something² - 9 In general, ...” April 18, 2019 Brent@GMATPrepNow posted a reply to y = 248 - 398x. Which of the following values of x gives in the Problem Solving forum “We can also test the answer choices.... (A) x = 200 means y = 248 - 398(200) = some number LESS THAN 248 (B) x = 100 means y = 248 - 398(100) = some number LESS THAN 248 (C) x = 0.5 means y = 248 - 398(0.5) = some number LESS THAN 248 (D) x = 0 means y = 248 - 398(0) = some number EQUAL TO ...” April 18, 2019 Brent@GMATPrepNow posted a reply to If sequence S has 120 terms, what is the 105th term of S? in the Data Sufficiency forum “Target question: What is the 105th term of S? Given: Sequence S has 120 terms Statement 1: The first term of S is −8. We have no information about the nature of the sequence. So, knowing the value of term 1 won''t help is determine the value of term 105 Since we cannot answer the ...” April 18, 2019 GMATGuruNY posted a reply to Verb-ing doubt in the Sentence Correction forum “NOUN + VERBing implies that the VERBing is a restrictive modifier. The purpose of a restrictive modifier is to SPECIFY the type of noun being discussed. Here, the restrictive modifier in blue implies the following: There are many types of planets. The sentence is not referring to all these ...” April 18, 2019 Brent@GMATPrepNow posted a reply to Does x + c = y + c ? in the Data Sufficiency forum “Target question: Does x + c = y + c ? This is a good candidate for rephrasing the target question. Take the equation x + c = y + c, and subtract c from both sides to get: x = y REPHRASED target question: Does x = y ? Aside: Here’s a video with tips on rephrasing the target question: ...” April 17, 2019 Brent@GMATPrepNow posted a reply to If n is a prime number greater than 3, what is the remainder in the Problem Solving forum “Choose ANY prime number greater than 3, and test it. If n = 5, then n² = 5² = 25 When 25 is divided by 12, the quotient is 2 and the remainder is 1 Answer: B Cheers, Brent” April 17, 2019 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 There are several values of x that satisfy statement 1. Here are two: Case a: x = 1. Notice that 2x + 1 = 2(1) + 1 = 3, which is odd. In this case, the answer to the target question is YES, x IS odd Case b: x = 2. Notice that 2x ...” April 17, 2019 GMATGuruNY posted a reply to If x and y are positive integers and in the Data Sufficiency forum “Statement 1: x=2 $$2^y =2^{2y-3}$$ Since each side has the same base, the two exponents must be equal: y = 2y-3 3 = y Since the values of x and y are known, the value of $$x^y$$ can be determined. SUFFICIENT. Statement 2: Thus, x=2. Same information as in Statement 1. Since Statement ...” April 17, 2019 GMATGuruNY posted a reply to There are 10 employees in an office. The table shows how in the Problem Solving forum “List of 10 pet values implied by the chart: 0, 0, 1, 1, 1, 2, 2, 3, 3, 3 Since the answer choices are all 3 or greater, the addition of the manager''s pet value will yield the following list of 11 values: 0, 0, 1, 1, 1, 2, 2, 3, 3, 3, M Since the new average must be equal to the median value ...” April 17, 2019 Brent@GMATPrepNow posted a reply to When 1,000 children were inoculated with a certain vaccine, in the Data Sufficiency forum “Target question: How many of the children developed inflammation but not fever? 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 (aka overlapping sets questions). ...” April 16, 2019 Brent@GMATPrepNow posted a reply to Is xy > 0? in the Data Sufficiency forum “Target question: Is xy > 0? Statement 1: x - y > -2 Let''s TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 5 and y = 1. In this case, xy = (5)(1) = 5. So, the answer to the target question is YES, xy IS greater than 0 Case b: ...” April 16, 2019 Brent@GMATPrepNow posted a reply to If x and y are positive integers and x = 10y + 5, what is in the Problem Solving forum “GIVEN: x = 10y + 5 Factor out 5 to get: x = 5(2y + 1) We can see that x is a multiple of 5, which also means x is divisible by 5, which means the remainder will by ZERO when x is divided by 5 Answer: A Cheers, Brent” April 16, 2019 Brent@GMATPrepNow posted a reply to Last Problem in OG12 Diagnostic in the Problem Solving forum “As with all VIACs (Variables In the Answer Choices questions), we can solve this via the INPUT-OUTPUT approach (as Mitch has done) or via an ALGEBRAIC approach. Typically, when the answer choices look complex (as they do here), I find the INPUT-OUTPUT approach easier. However, the algebraic ...” April 16, 2019 GMATGuruNY posted a reply to Computer-based activities in the Critical Reasoning forum “In a strengthen CR, the OA SUPPORTS THE PASSAGE. In an inference CR, the PASSAGE SUPPORTS THE OA. Here, the OA supports the passage. The result is a strengthen CR. Since the OA supports the conclusion, its negation naturally will weaken the conclusion.” April 16, 2019 GMATGuruNY posted a reply to OG Most of the country's biggest daily newspapers in the Sentence Correction forum “This is the comparison conveyed by the green sentence above. Here, each blue portion has a subject (the company) and a verb (had) and thus constitutes a clause. The result is a logical comparison. This is the comparison implied by the incorrect red sentence above. The first blue portion ...” April 16, 2019 Brent@GMATPrepNow posted a reply to Which of the following is equivalent to in the Problem Solving forum “Here''s another approach.... Take: $$\frac{x+y}{3}-\frac{x-y}{4}$$ Find common denominator: $$\frac{4(x+y)}{12}-\frac{3(x-y)}{12}$$ Expand numerators: $$\frac{4x+4y}{12}-\frac{3x-3y)}{12}$$ Combine fractions: $$\frac{(4x+4y)-(3x-3y)}{12}$$ Simplify numerator: $$\frac{x+7y}{12}$$ ...” April 15, 2019 Brent@GMATPrepNow posted a reply to A man spends$48 to buy 6 hamburgers and 8 colas for his in the Problem Solving forum
“Let H = price of one hamburger Let C = price of one cola A man spends $48 to buy 6 hamburgers and 8 colas for his office workers. 6H + 8C = 48 The next day, he buys 5 hamburgers and 4 colas and spends$32. 5H + 4C = 32 Assuming the prices of hamburgers and colas remain constant, what ...”
April 15, 2019
Brent@GMATPrepNow posted a reply to Alice, Benjamin, and Carol each try independently to win a in the Problem Solving forum
“P(exactly 2 win) = P(A wins and B wins and C loses OR B wins and C wins and A loses OR A wins and C wins and B loses) = P(A wins and B wins and C loses) + P(B wins and C wins and A loses) + P(A wins and C wins and B loses) Let''s calculate each probability P(A wins and B wins and C loses) = ...”
April 15, 2019
GMATGuruNY posted a reply to Three salespeople, Dan, Matt, and Nicole, earned annual in the Problem Solving forum
“D:M:N = 3:5:8. The sum of the parts of the ratio = 3+5+8 = 16. The values in red indicate the following: Nicole''s fraction of the total = 8/16 = 1/2. Since Nicole''s $28,000 is 1/2 of the total, the total =$56,000. The correct answer is E.”
April 15, 2019
GMATGuruNY posted a reply to Together, 15 type A machines and 7 type B machines can in the Problem Solving forum
“Let the job = 44 units. Since 15A+7B take 4 hours to complete the 44-unit job, the rate for 15A+7B = w/t = 44/4 = 11 units per hour. Since 8B+15C take 11 hours to complete the 44-unit job, the rate for 8B+15C = w/t = 44/11 = 4 units per hour. Adding together 15A+7B=11 and 8B+15C=4, we get: ...”
April 15, 2019
GMATGuruNY posted a reply to Mark has fewer than 9 coins. Each coin is either a quarter in the Data Sufficiency forum
“Statement 1: 25Q + 10D = 170 5Q + 2D = 34 To minimize the number of coins, we must maximize the value of Q. If Q=6, then D=2, with the result that 5Q + 2D = (5*6) + (2*2) = 34. In this case, the total number of coins = 6+2 = 8. If the value of Q decreases, then the total number of coins ...”
April 15, 2019
GMATGuruNY posted a reply to 12^(1/2) + 108^(1/2) + 48^(1/2) = in the Problem Solving forum
“√12 + (√9 * √12) + (√4 * √12) = √12 + 3√12 + 2√12 = 6√12 = 6 * √4 * √ 3 = 12√3 The correct answer is A.”
April 15, 2019
GMATGuruNY posted a reply to If n is a positive integer greater than 6, what is the in the Data Sufficiency forum
“Approach 1: Since n is greater than 6, and the statements refer to n², make a list of perfect squares greater than 6²: n² = 49, 64, 81, 100, 121, 144, 169, 196, 225. Subtracting 1 from these values, we get the following options for n² - 1: n² - 1 = 48, 63, 80, 99, 120, 143, 168, 195, ...”
April 15, 2019
GMATGuruNY posted a reply to Which of the following is equivalent to in the Problem Solving forum
“Let x=2 and y=1, with the result that (x+y)/3 - (x-y)/4 = 1 - 1/4 = 3/4. The correct answer must yield 3/4 when x=2 and y=1. Only D works: (7y+x)/12 = (7*1 + 2)/12 = 9/12 = 3/4 The correct answer is D.”
April 15, 2019
Brent@GMATPrepNow posted a reply to If n is an integer, is (100−n)n an integer? in the Data Sufficiency forum
“Target question: Is (100 - n)/n an integer? Statement 1: n > 4 Let''s TEST some values There are infinitely many values of n that satisfy statement 1. Here are two: Case a: n = 5. In this case, (100 - n)/n = (100 - 5)/5 = 95/5 = 19. So, the answer to the target question is YES, (100 - ...”
April 14, 2019
Brent@GMATPrepNow posted a reply to f(x) = x^2 - x. For which of the following values of a is in the Problem Solving forum
“GIVEN: f(x) = x² - x So, f(8) = 8² - 8 = 56 I. a = -7 So, f(-7) = (-7)² - (-7) = 56 This means f(a) ≥ f(8) Check the answer choices. . . ELIMINATE B and C II. a = -8 So, f(-8) = (-8)² - (-8) = 72 This means f(a) ≥ f(8) Check the answer choices. . . ELIMINATE A II. a = -9 ...”
April 14, 2019
Brent@GMATPrepNow posted a reply to What is the largest value of integer n such that in the Problem Solving forum
“98 = (2)(7)(7) = (2^1)(7^2) So, 98^98 = (2^1)(7^2)]^98 = (2^98)(7^196) What is the largest value of integer n such that 98^98 is divisible by 7^n? Since 98^98 = (2^98)(7^196), the largest value of n is 196 Answer: E Cheers, Brent”
April 14, 2019
GMATGuruNY posted a reply to In a certain office, 50 percent of the employees are college in the Data Sufficiency forum
“Let T = the total number of employees. Since 60% of the employees are over 40, we get: Over 40 = 0.6T 30% of those over 40 -- in other words, 30% of the expression in blue -- have master''s degrees. Thus: Over 40 with master''s = 0.3(0.6T). To calculate the value of the expression in ...”
April 14, 2019
GMATGuruNY posted a reply to Dwight and Mose decide to build a new barn on their farm, in the Problem Solving forum
“Every time Dwight does 1/4 of the remaining work, 3/4 of the work remains. Every time Mose does 1/6 of the remaining work, 5/6 of the work remains. When Mose starts his third shift, Dwight has completed 3 shifts, while Mose has completed 2 shifts. Thus, the remaining work at the start of Mose''s ...”
April 14, 2019
GMATGuruNY posted a reply to In a law firm, 72% of the employees are associates and 54% in the Problem Solving forum
“Let the total number of employees = 100, implying that the total number of associates = 72% of 100 = 72 and that the number of senior associates = 54% of 100 = 54. The prompt should make clear that every associate is either a junior associate or senior associate, yielding the following equation: ...”
April 14, 2019
GMATGuruNY posted a reply to A library branch originally contained 18360 volumes, 30% of in the Problem Solving forum
“Since the answer choices are PERCENTS, the total number of books can be ANY POSITIVE VALUE. 30% = 3/10, implying a denominator of 10. Let the total number of books = the product of the three denominators 10, 3 and 3 = 10*3*3 = 90. Since 30% of the books are fiction, the number of fiction books ...”
April 12, 2019
Brent@GMATPrepNow posted a reply to A certain series is defined by the following recursive rule: in the Problem Solving forum
“I''m not crazy about this question. Typically, when we talk about series, Sn represents the SUM of the first n terms of that series. However, based on the official answer, Sn seems to represent the value of TERM n. Cheers, Brent”
April 12, 2019
e-GMAT posted a reply to GMAT Quantitative: Question of the Week in the GMAT Math forum
“Hello all, We have added a new question this week in our Question of the Week series. Give it a try. Question of the Week- 4 Also, try the previous problems of this series, if you have not done it yet. Stay tuned for more questions. Happy learning. :) Regards,”
April 12, 2019
e-GMAT posted a new topic called e-GMAT Question of the Week #4 in the Problem Solving forum
“While working individually, each of A, B, C and D can produce 60 units of a certain item in a, b, c and d hours respectively, where a, b, c, d are consecutive integers in increasing order. If A and C together can produce 60 units in more than 2 hours, then which of the following cannot be the time ...”
April 12, 2019
GMATGuruNY posted a reply to Heavy commitment by an executive in the Sentence Correction forum
“that-clause includes its own subject and verb and thus does not require an additional agent. In the blue that-clause above, the subject for will meet (verb) is a system of import relief laws. Since it is clear that A SYSTEM will meet the strategic needs, no additional agent is required. An ...”
April 11, 2019
GMATGuruNY posted a reply to Mary and Kate are running clockwise around a circular track in the Problem Solving forum
“Since Mary is behind Kate by 250 meters -- half the circumference of the track -- she will catch up to Mary when she has traveled 250 meters more than Kate. To catch up to Kate a second time, Mary must then travel one more lap than Kate -- in other words, 500 meters more than Kate. Implication: ...”
April 11, 2019
Brent@GMATPrepNow posted a reply to Mary and Kate are running clockwise around a circular track in the Problem Solving forum
“To get a better idea of what''s happening, let''s sketch the set-up: https://i.imgur.com/SwHzFJD.png Mary is faster than Kate, we can say that Kate has a 250 meter head start. In other words, when Mary closes that 250-meter gap, she will pass Kate for the FIRST time. ...”
April 11, 2019
GMATGuruNY posted a reply to Heavy commitment by an executive in the Sentence Correction forum
“The bad weather makes it difficult to work outdoors. Here, the infinitive in blue is not immediately preceded by an agent: the sentence does not specify WHO is intended TO WORK. The implication is that the agent for the blue infinitive is not a specific person but people IN GENERAL, as follows: ...”
April 11, 2019
e-GMAT posted a reply to GMAT Quantitative: Question of the Week in the GMAT Math forum
“Hello all, We have posted the Official Solution of the Question of the Week #3 Happy learning. :) Regards,”
April 11, 2019
e-GMAT posted a reply to Question of the Week - 3 (The value of the variable E is...) in the Problem Solving forum
“Solution Given: In this question, we are given that • The value of the variable E is determined by adding the reciprocals of the first 10 even natural numbers. To find: We need to determine • Among the given options, which one can be a possible value of the reciprocal of E. Approach ...”
April 11, 2019
Brent@GMATPrepNow posted a reply to What is the sum of the cubes of the first ten positive? in the Problem Solving forum
“Let''s look for a pattern 1³ = 1 = 1² 1³ + 2³ = 9 = 3² 1³ + 2³ + 3³ = 36 = 6² 1³ + 2³ + 3³ + 4³ = 100 = 10² 1³ + 2³ + 3³ + 4³ + 5³ = 225 = 15² See the pattern yet? 1 + 2 = 3 3 + 3 = 6 6 + 4 = 10 10 + 5 = 15 First we add 2, then we add 3, then 4, then 5, etc ...”
April 11, 2019
Brent@GMATPrepNow posted a reply to If 0.00012345 is between 1/10^n and 1/10^{n-1}, what is the in the Problem Solving forum
“We need to examine powers of 10 that are smaller than AND greater than 0.00012345 We know that: 0.0001 < 0.00012345 < 0.001 Rewrite as FRACTIONS to get: 1/10,000 < 0.00012345 < 1/1,000 Rewrite as POWERS OF 10 to get: 1/10⁴ < 0.00012345 < 1/10³ We''re told that 0.00012345 ...”
April 10, 2019
Brent@GMATPrepNow posted a reply to GMAT Prep Practice Test Quant Questions #4 in the GMAT Math forum
“ Given: wx = y Target question: What is the value of xy ? Statement 1: wx²= 16 We can rewrite this as: (wx)(x) = 16 Since wx = y, we can replace wx with y to get: (y)(x) = 16 So, the answer to the target question is xy = 16 Since we can answer the target question with certainty, ...”
April 9, 2019
Brent@GMATPrepNow posted a reply to A camera lens filter kit containing 5 filters sells for $in the Problem Solving forum “2 of them are priced at$10.45 each, 2 at $12.05 each, 1 at$17.50 TOTAL cost when purchased individually = (2 x $10.45) + (2 x$12.05) + (1 x $17.50) =$20.90 + $24.10 +$17.50 = $62.50 The amount saved by purchasing the kit is what percent of the total price of the 5 filters purchased ...” April 9, 2019 Brent@GMATPrepNow posted a reply to Machine A produces pencils at a constant rate of 9000 in the Problem Solving forum “To MINIMIZE machine B''s operating time, we must MAXIMIZE the time machine A''s operating time. So, let machine A operate for the full 8 hours. In 8 hours, machine A produces 72,000 pencils So, the number of pencils machine B must make = 100,000 - 72,000 = 28,000 Time = output/rate So, ...” April 9, 2019 GMATGuruNY posted a reply to How many rectangles are found in the lattice below? in the Problem Solving forum “https://i.postimg.cc/Z0xg3MXX/lattice.png To form a rectangle, we must combine as HORIZONTAL LENGTH with a VERTICAL LENGTH: Horizontal length: Number of ways to choose a horizontal length of 1: AB, BC, CD, DE, EF = 5 Number of ways to choose a horizontal length of 2: AC, BD, CE, DF = 4 ...” April 9, 2019 GMATGuruNY posted a reply to If x is a positive integer, is the remainder 0 when in the Data Sufficiency forum “$$3^x + 1$$ will yield a remainder of 0 when divided by 10 if it has a units digit of 0. 3¹ --> units digit of 3. 3² --> units digit of 9. (Since the product of the preceding units digit and 3 = 3*3 = 9.) 3³ --> units digit of 7. (Since the product of the preceding units digit and ...” April 9, 2019 GMATGuruNY posted a reply to If d is a positive integer and f is the product of the first in the Data Sufficiency forum “30! = 30*29*28*....*3*2*1. Statement 1: To determine the greatest possible value for d, we need to know the number of 10''s contained within 30! Since 10=2*5, EVERY COMBINATION OF 2*5 contained within the prime-factorization of 30! will yield a 10. The prime-factorization of 30! is composed ...” April 9, 2019 GMATGuruNY posted a reply to Last year, the price of a jar of peanut butter at a certain in the Problem Solving forum “The price of a jar of peanut butter at a certain store was P dollars and the price of a jar of jelly at the same store was J dollars, where J=2P. Let P = 10 and J = 20 This year, the price of peanut butter increased by 20% and the price of jelly decreased by 20% New P = 10 + (20% of 10) = 10 + ...” April 9, 2019 Brent@GMATPrepNow posted a reply to Any decimal that has only a finite number of nonzero digits in the Data Sufficiency forum “Target question: Is r/s a terminating decimal? Statement 1: 90 < r < 100 There are several pairs of values that meet this condition. Here are two: Case a: r = 91 and s = 2, in which case r/s = 91/2 = 45.5 = a terminating decimal Case b: r = 91 and s = 3, in which case r/s = 91/3 = ...” April 8, 2019 Brent@GMATPrepNow posted a reply to A sewing store buys fabric X by the bolt at the wholesale in the Data Sufficiency forum “Target question: What is the wholesale price of a bolt of fabric X? Given: Each bolt contains 50 meters of fabric X Statement 1: The store sells fabric X for$6.25 per meter. No information about the relationship between the WHOLESALE price and the RETAIL price Statement 1 is NOT ...”
April 8, 2019
Brent@GMATPrepNow posted a reply to There are 10 books on a shelf: 5 English books, 3 Spanish in the Problem Solving forum
“Let''s use the complement. That is, P(Event A happening) = 1 - P(Event A not happening) So, here we get: P( 2 different languages) = 1 - P(NOT 2 different languages) So, we can write: P(2 different languages) = 1 - P(the 2 languages are the SAME) P(the 2 languages are the SAME) P(the 2 ...”
April 8, 2019
GMATGuruNY posted a reply to If the median and average (arithmetic mean) of a set of 4 di in the Data Sufficiency forum
“In ascending order, let the four numbers = a, b, c, d. Since the average of the 4 numbers = 10, we get: (a+b+c+d)/4 = 10 a+b+c +d = 40 Since the median of the 4 numbers = 10, we get: (b+c)/2 = 10 b+c = 20 Subtracting the blue equation from the red equation, we get: (a+b+c+d) - (b+c) = 40-20 ...”
April 8, 2019
Brent@GMATPrepNow posted a reply to Any feedback on the Orion GMAT prep? in the Helpful Resources forum
“Sorry - I know almost nothing about that company. Cheers, Brent”
April 7, 2019
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“Data Sufficiency lesson #6: - Rephrasing the Target Question Video : https://www.youtube.com/watch?v=MyG1K3ee69w Cheers, Brent”
April 7, 2019
Brent@GMATPrepNow posted a reply to In a certain game only one player can win and only one in the Data Sufficiency forum
“Target question: What is the probability that Katelyn wins at least one of the 3 games? This is a good candidate for rephrasing the target question. In order to determine P(Katelyn wins at least one of the 3 games), we need to know the probability that Katelyn wins if they play ONE game. We ...”
April 7, 2019
Brent@GMATPrepNow posted a reply to Question of the Week - 3 (The value of the variable E is...) in the Problem Solving forum
“A fast approach is to use some estimation. E = 1/2 + 1/4 + 1/6 + 1/8 + 1/10 + 1/12 + 1/14 + 1/16 + 1/18 + 1/20 ≈ 0.5 + 0.25 + 0.15 + 0.1 + 0.1 + 0.1 + 0.05 + 0.05 + 0.05 + 0.05 ≈1.4 Which of the following can be a possible value of the reciprocal of E? The reciprocal of E ...”
April 7, 2019
e-GMAT posted a reply to GMAT Quantitative: Question of the Week in the GMAT Math forum
“Hello all, We have added a new question this week in our Question of the Week series. Give it a try. Question of the Week- 3 Also, try the previous problems of this series, if you have not done it yet. Stay tuned for more questions. Happy learning. :) Regards,”
April 7, 2019
e-GMAT posted a new topic called Question of the Week - 2 (The value of the variable E is...) in the Problem Solving forum
“The value of the variable E is determined by adding the reciprocals of the first 10 even natural numbers. Which of the following can be a possible value of the reciprocal of E? A. 0.154 B. 0.1818 C. 0.667 D. 2 E. 3.03 To access all questions: Consolidated list of Questions of the Week”
April 7, 2019
GMATGuruNY posted a reply to Mixture A is 15 percent alcohol, and mixture B is 50 percent in the Problem Solving forum
“A = 15% alcohol B = 50% alcohol The MIXTURE of A and B = 30% alcohol To determine the ratio of A to B, use ALLIGATION -- a very efficient way to handle mixture problems. Step 1: Plot the 3 percentages on a number line, with the percentages for A and B (15% and 50%) on the ends and the ...”
April 7, 2019
GMATGuruNY posted a reply to A museum sold 30 tickets on Saturday. Some of the tickets so in the Data Sufficiency forum
“Let G = the number of general tickets. Since a total of 30 tickets are sold, the number of special exhibit tickets = 30-G. Since general tickets = $10 each and special exhibit tickets =$70 each, we get: Total revenue = 10G + 70(30-G) = 10G + 2100 - 70G = 2100 - 60G. Statement 1: 1570 < ...”
April 7, 2019
GMATGuruNY posted a reply to If 500 is the multiple of 100 that is closest to X and 400 in the Data Sufficiency forum
“Statements combined: Case 1: X=460, with the result that 500 is the multiple of 100 closest to X Y=360, with the result that 400 is the multiple of 100 closest to Y In this case, X+Y=820, so the multiple of 100 closest to X+Y is 800. Case 2: X=490, with the result that 500 is the multiple of ...”
April 7, 2019
Brent@GMATPrepNow posted a reply to Is the positive integer x an even number? in the Data Sufficiency forum
“OA=E Target question: Is x an even number? Jump straight to..... Statements 1 and 2 combined There are infinitely many values of x that satisfy BOTH statements. Here are two: Case a: x = 32. In this case, the answer to the target question is YES, x IS an even number Case b: x = 17. ...”
April 6, 2019
Brent@GMATPrepNow posted a reply to During a trip that they took together, Carmen, Juan, Maria, 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”
April 6, 2019
Brent@GMATPrepNow posted a reply to If a certain animated cartoon consists of a total of 17,280 in the Data Sufficiency forum
“Target question: How many minutes will it take to run the cartoon? Given: cartoon consists of a total of 17,280 frames Statement 1: The cartoon runs without interruption at the rate of 24 frames per second. Time = (output)/(rate) So, time = (17,280 frames)/(24 frames per second) NOTE: ...”
April 6, 2019
Brent@GMATPrepNow posted a reply to While a family was away on vacation, they paid 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) = ...” April 6, 2019 Brent@GMATPrepNow posted a reply to Last year$48,000 of a certain store's profit was shared 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 + ...” April 6, 2019 Brent@GMATPrepNow posted a reply to Alice is twice as old as Brian and Cathy is 6 years in the Problem Solving forum “GIVEN: Alice is a years old Alice is twice as old as Brian This also means Brian is HALF as old as Alice So, Brian''s age = a/2 Cathy is 6 years younger than Brian So, Cathy''s age = (Brian''s age) - 6 So, Cathy''s age = (a/2) - 6 How old is Cathy in terms of a ? Cathy''s age = (a/2) - ...” April 6, 2019 Brent@GMATPrepNow posted a reply to For all numbers m and n... in the Problem Solving forum “GOAL: Find the value of 4?3 GIVEN: m?n = (2m - n)(m+ n) So, 4?3 = (2(4) - 3)(4+ 3) = (5)(7) = 35 Answer: A Cheers, Brent” April 6, 2019 Brent@GMATPrepNow posted a reply to If x and y are two points on the number line what is the in the Data Sufficiency forum “Target question: What is the value of x + y? Statement 1: 6 is halfway between x and y. KEY CONCEPT: The average (arithmetic mean) of 2 numbers is HALFWAY between those 2 numbers. For example, the average of 1 and 9 is 5. Notice that 5 is HALFWAY between 1 and 9. So, statement is ...” April 6, 2019 Brent@GMATPrepNow posted a reply to The residents of Town X participated in a survey to in the Problem Solving forum “---------ASIDE-------------------- A little extra background on standard deviations above and below the mean If, for example, a set has a standard deviation of 4, then: 1 standard deviation = 4 2 standard deviations = 8 3 standard deviations = 12 1.5 standard deviations = 6 0.25 ...” April 6, 2019 Brent@GMATPrepNow posted a reply to In the xy-coordinate system, line k has slope 1/2 and passes in the Problem Solving forum “Let''s first determine the equation of line k A quick approach is the write the equation of line k in slope y-intercept form: y = mx + b, where m = slope and b = y-intercept. We''re told that the slope = 0.5 and the point (0,5) tells us that the y-intercept is 5 So, the equation of line k is: ...” April 6, 2019 Brent@GMATPrepNow posted a reply to In a certain office, the ratio of men to women is 3/4. in the Problem Solving forum “Another approach: Let M = number of men CURRENTLY in the office Let W = number of women CURRENTLY in the office In a certain office, the ratio of men to women is CURRENTLY 3/4. We can write: M/W = 3/4 Cross multiply to get: 4M = 3W Rewrite as: 4M - 3W = 0 If 10 men were added to the ...” April 6, 2019 Brent@GMATPrepNow posted a reply to In a certain office, the ratio of men to women is 3/4. in the Problem Solving forum “In a certain office, the ratio of men to women is 3/4. This tells us that, out of EVERY 7 people in the office, 3 are men and 4 are women. It also tells us that the TOTAL number of men and women currently in the office is divisible by 7 When we check the answer choices, we see that A, B and E ...” April 6, 2019 GMATGuruNY posted a reply to One legacy of Madison Avenue's in the Sentence Correction forum “Generally, a when-clause refers to an action performed at a particular moment: When Mary entered the room, John smiled. Here, the usage of when implies that the action in blue happened at a particular moment. An as-clause refers to an action performed over an extended period of time: Adam sang ...” April 6, 2019 GMATGuruNY posted a reply to The 32 species that make up the dolphin family are closely r in the Sentence Correction forum “There is no reason to repeat which in the OA. Even if more than one verb is attributed to COMMA + WHICH, the usage of one which should suffice.” April 6, 2019 GMATGuruNY posted a reply to In a nationwide poll, N people were interviewed. If 1/4 in the Problem Solving forum “Let N=12. Number who answered yes to question 1 = (1/4)12 = 3. Number who also answered yes to question 2 = (1/3)3 = 1. Number who didn''t answer yes to both questions = 12-1 = 11. This is our target. Now we plug N=12 into the answers to see which yields our target of 11. Only E works: ...” April 6, 2019 April 6, 2019 Brent@GMATPrepNow posted a reply to In the diagram above, points A, B, C, D, and E represent the in the Problem Solving forum “points A, B, C, D, and E represent the five teams in a certain league in which each team must play each of the other teams exactly once. Let''s first determine the total number of games that will be played. There are 5 teams, so each team will play 4 games (since a team can''t play itself) So, ...” April 6, 2019 Brent@GMATPrepNow posted a reply to John and Mary were each paid x dollars in advance to do a in the Problem Solving forum “One approach: 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 ...” April 5, 2019 Brent@GMATPrepNow posted a reply to On a certain sightseeing tour, the ratio of the number in the Data Sufficiency forum “Let W = # of women Let M = # of men Let C = # of children Target question: What is the value of M? Given: The ratio of the number of women to the number of children was 5 to 2 In other words, W : C = 5 : 2 Statement 1: On the sight-seeing tour, the ratio of the number of children to ...” April 5, 2019 Brent@GMATPrepNow posted a reply to Five friends - Ross, Phoebe, Chandler, Joey, and Monica in the Problem Solving forum “Take the task of feeding the 5 friends and break it into stages. We’ll begin with the most restrictive stage(s). Stage 1: Select a pizza for Phoebe Since Phoebe will only eat Margherita pizza, there''s only 1 pizza we can serve her. So, we can complete stage 1 in 1 way Stage 2: ...” April 5, 2019 Brent@GMATPrepNow posted a reply to The y intercept of a line L is 4. If the slope of L is in the Problem Solving forum “Let''s draw a bunch of lines with a negative slope AND have a y-intercept of 4 (ie, passes through the point (0,4)) We get: http://i1168.photobucket.com/albums/r500/GMATPrepNow/x-int_zpsswbinqns.png As we can see, the x-intercept can have ANY POSITIVE value. So, the x-intercept COULD be 6, ...” April 5, 2019 GMATGuruNY posted a reply to Is x < 0? in the Data Sufficiency forum “Statement 1: x³ < -1 The cube of x will be negative only if x itself is negative. Thus, x < 0. SUFFICIENT. Statement 2: x³ + x < -1 x(x² + 1) < -1 Since the square of a value cannot be negative, x² ≥ 0, with the result that the factor in blue must be POSITIVE. ...” April 5, 2019 GMATGuruNY posted a reply to A pizza shop sold small pizzas for$4.5 in the Problem Solving forum
“The GMAT would list the answer choices in ascending or descending order, as follows: We can PLUG IN THE ANSWERS, which represent the number of small pizzas. The average cost per pizza = 5050/500 ≈ $10. Since the average cost ($10) is much closer to the price of a large pizza ($12.50) than ...” April 5, 2019 Brent@GMATPrepNow posted a reply to In the rectangular solid above, if each dimession of the in the Data Sufficiency forum “Here''s a very similar (official) practice question: https://www.beatthegmat.com/volume-of-rectangular-solid-t273956.html Cheers, Brent” April 5, 2019 Brent@GMATPrepNow posted a reply to Is x < 0? in the Data Sufficiency forum “Target question: Is x < 0? Two important rules: ODD exponents preserve the sign of the base. So, (NEGATIVE)^(ODD integer) = NEGATIVE and (POSITIVE)^(ODD integer) = POSITIVE An EVEN exponent always yields a positive result (unless the base = 0) So, (NEGATIVE)^(EVEN integer) = ...” April 5, 2019 Brent@GMATPrepNow posted a reply to In the sequence S, each term after the first is twice the in the Problem Solving forum “term1 = 3 term2 = (3)(2) = (3)(2¹) term3 = (3)(2)(2) = (3)(2²) term4 = (3)(2)(2)(2) = (3)(2³) term5 = (3)(2)(2)(2)(2) = (3)(2⁴) . . term14 = (3)(2^13) term15 = (3)(2^14) term16 = (3)(2^15) What is the sum of the 14th, 15th, and 16th terms in sequence S? Sum = (3)(2^13) + ...” April 5, 2019 Brent@GMATPrepNow posted a reply to If x, y, and d are integers and d is odd, are both x and y in the Data Sufficiency forum “ Given: x, y, and d are integers and d is odd Target question: Are both x and y divisible by d? Statement 1: x+y is divisible by d. Let''s TEST some values. There are several values of x, y and d that satisfy statement 1. Here are two: Case a: x = 6, y = 9 and d = 3. Notice that 6+9 = ...” April 4, 2019 Brent@GMATPrepNow posted a reply to m and n are positive integers. Are m and n consecutive integ in the Data Sufficiency forum “ Given: m and n are positive integers. Target question: Are m and n consecutive integers? Statement 1: m² + n² = 5 Since m and n are positive integers, there are only two possible solutions: Solution #1: m = 1 and n = 2 Solution #2: m = 2 and n = 1 In BOTH possible cases, the ...” April 3, 2019 e-GMAT posted a reply to GMAT Quantitative: Question of the Week in the GMAT Math forum “Hello all, We have posted the Official Solution of the Question of the Week #1 and Question of the Week - 2 Happy learning. :) Regards,” April 3, 2019 e-GMAT posted a reply to Question of the Week - 2 (If x and y are non-zero integers ) in the Problem Solving forum “Solution Given: In this question, we are given that • The numbers x and y are non-zero integers. • Also, |x – 3| ≤ 2 and -1 ≤ y ≤ 8. To find: We need to determine • The least value of x/y lies in which of the given ranges. Approach and Working: For the non-zero integer ...” April 3, 2019 GMATGuruNY posted a reply to Fossils of feathered dinosaurs - GMAT prep Exam pack 1 in the Sentence Correction forum “A general truth is something that is true not just at a particular moment but is true IN GENERAL. Mary plays the saxophone. Here, the portion in blue expresses a general truth about Mary. To express a GENERAL TRUTH, we use the simple present tense. The SC above is intended to express a general ...” April 2, 2019 GMATGuruNY posted a reply to While making a non-stop trip, a bus averaged m mph for the in the Data Sufficiency forum “Distance traveled in the first 5 hours = 5m. Distance traveled in the remaining 4 hours = 4n. Average speed for the entire 9-hour trip = (5m + 4n)/9. To determine the average speed for the entire trip, we need to know the value of 5m+4n. Question stem, rephrased: What is the value of 5m+4n? ...” April 2, 2019 GMATGuruNY posted a reply to OG13 - Q20 in the Sentence Correction forum “The OA does not make a comparison. to double X = to increase X by 100% OA: Personal spending in the Julv-September quarter would more than double the...growth rate. Conveyed meaning: Personal spending in the July-September quarter would increase the growth rate by more than 100%.” April 2, 2019 Brent@GMATPrepNow posted a reply to If Norbert can cut up one plastic six pack container in 30 in the Problem Solving forum “We can solve this question by applying equivalent ratios For every 30 seconds that elapse, Norbert can cut up 1 plastic six-pack container In other words, for every 0.5 MINUTES that elapse, Norbert can cut up 1 plastic six-pack container Let t = the time (in MINUTES) to cut up 512 plastic ...” April 2, 2019 GMATGuruNY posted a reply to OG12, Q18 in the Sentence Correction forum “OA: Plants are more efficient than fungi at acquiring carbon, in the form of carbon dioxide. Here, the modifier in green is an adverb in that it describes UNDER WHAT CIRCUMSTANCE the preceding blue action happens. Under what circumstance ARE plants MORE EFFICIENT at acquiring carbon? Under the ...” April 2, 2019 Brent@GMATPrepNow posted a reply to For what percent of those tested for a certain infection was in the Data Sufficiency forum “I just want to point out that Jay has done a perfect job employing a technique known as the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of patients, and the ...” April 2, 2019 GMATGuruNY posted a reply to Barry walks from one end to the other of a 30-meter long in the Problem Solving forum “Let B = Barry''s rate and W = the walkway''s rate. The distance can be ANY VALUE. Let the distance = 240 meters. WITH the walkway, the time = 30 seconds: Here, Barry and the walkway WORK TOGETHER, so we ADD their rates: B+W = d/t = 240/30 = 8 meters per second. AGAINST the walkway, the ...” April 1, 2019 GMATGuruNY posted a reply to 2+2+2^2+2^3+2^4+2^5+2^6+2^7+2^8=? in the Problem Solving forum “2⁸ = 256 2⁷ = 128 Thus: 2⁸ + 2⁷ + 2⁶ + 2⁵ + 2⁴ + 2³ + 2² + 2 + 2 = 256 + 128 + (around 100) ≈ 500. Only A is viable: 2⁹ = 512. The correct answer is A.” April 1, 2019 Brent@GMATPrepNow posted a reply to What is the number of cans that can be packed in a certain in the Data Sufficiency forum “Target question: What is the number of cans that can be packed in a certain carton? Let''s head straight to..... Statements 1 and 2 combined Consider these two conflicting cases (that satisfy BOTH statements): Case a: the dimensions of the box are numbers are 1 x 1 x 2304 (inches), in ...” April 1, 2019 Brent@GMATPrepNow posted a reply to 2+2+2^2+2^3+2^4+2^5+2^6+2^7+2^8=? in the Problem Solving forum “Let''s look for a pattern... We want: 2 + 2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 + 2^8 = ? 2 + 2 + 2^2 = 4 + 4 = 8 = 2^3 So, 2 + 2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 + 2^8 = 2^3 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 + 2^8 2^3 + 2^3 = 2(2^3) = 2^4 So, 2^3 + 2^3 + 2^4 + 2^5 + 2^6 + 2^7 + 2^8 = 2^4 + ...” April 1, 2019 Brent@GMATPrepNow posted a reply to If n is the smallest of three consecutive positive integers in the Problem Solving forum “There''s a nice rule says: The product of k consecutive integers is divisible by k, k-1, k-2,...,2, and 1 So, for example, the product of any 5 consecutive integers will be divisible by 5, 4, 3, 2 and 1 Likewise, the product of any 11 consecutive integers will be divisible by 11, 10, 9, . . . 3, ...” April 1, 2019 Brent@GMATPrepNow posted a reply to A collection of 36 cards consists of 4 sets of 9 cards in the Data Sufficiency forum “Target question: What is the number on the card? Given: A collection of 36 cards consists of 4 sets of 9 cards in each set are numbered 1 through 9. Statement 1: The units digit of the sum of the numbers on the remaining 35 cards is 6. 1+2+3+4+5+6+7+8+9=45 Since there are 4 sets of ...” April 1, 2019 Brent@GMATPrepNow posted a reply to If x = 1 – 2y, what is z? in the Data Sufficiency forum “Target question: What is the value of z? Given: x = 1 – 2y Statement 1: 5x + 10y + z = 5 Replace x with 1 – 2y to get: 5(1 – 2y) + 10y + z = 5 Expand: 5 - 10y + 10y + z = 5 Simplify: 5 + z = 5 Solve: z = 0 Since we can answer the target question with certainty, statement 1 is ...” April 1, 2019 Brent@GMATPrepNow posted a reply to Is x > 0? in the Data Sufficiency forum “Target question: Is x > 0? Statement 1: x² > 0 This statement doesn''t feel sufficient, so I''ll TEST some values. There are several values of x that satisfy statement 1. Here are two: Case a: x = 1. In this case, the answer to the target question is YES, it is the case that x > ...” April 1, 2019 Brent@GMATPrepNow posted a reply to If y is the smallest positive integer such that 3,150 in the Problem Solving forum “Key concept: The prime factorization of a perfect square (the square of an integer) will have an EVEN number of each prime. For example, 36 = (2)(2)(3)(3) And 400 = (2)(2)(2)(2)(5)(5) Likewise, 3150y must have an EVEN number of each prime in its prime factorization. So, 3150y = ...” April 1, 2019 Brent@GMATPrepNow posted a reply to If 3 less than twice a certain number is equal to 2 more in the Problem Solving forum “Let x be the number 3 less than twice a certain number is equal to 2 more than 3 times the number We can write: 2x - 3 = 3x + 2 So: -3 = x + 2 Solve: -5 = x 5 less than 5 times the number is 5 times the number = 5(-5) = -25 So, 5 less than 5 times the number = -25 - 5 = -30 Answer: A ...” March 31, 2019 Brent@GMATPrepNow posted a reply to Which of the following inequalities is an algebraic in the Problem Solving forum “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 < -k Note: these rules assume that k is positive (A) |x| ≤ 3 ...” March 31, 2019 e-GMAT posted a new topic called Question of the Week - 2 (If x and y are non-zero integers ) in the Problem Solving forum “If x and y are non-zero integers and |x – 3| ≤ 2 and -1 ≤ y ≤ 8 then the least value of x/y lies in which of the following range? A. Between -5.5 and -4.5 B. Between -4.5 and -3.5 C. Between -3.5 and -2.5 D. Between -2.5 and -1 E. Greater than -1” March 30, 2019 e-GMAT posted a reply to e-GMAT Question of the Week #1 in the Problem Solving forum “Solution Given: The number n is the product of the first 49 natural numbers The numbers $$\frac{n}{24^p}$$ and $$\frac{n}{36^q}$$ are integers To find: The maximum possible value of p + q Approach and Working: When it is given that $$\frac{n}{24^p}$$ is an integer, it necessarily means p ...” March 30, 2019 GMATGuruNY posted a reply to Cars emerging from a motorway arrive at a junction that in the Problem Solving forum “We can PLUG IN THE ANSWERS, which represent the number of cars in the left lane. Answer choice C: 1700 If 700 cars per hour were diverted from the left lane to the right lane, the number of cars entering the right lane per hour would be twice as big as the number of cars entering the left lane ...” March 30, 2019 Brent@GMATPrepNow posted a reply to In how many ways a criket team consisting of 5 batsmen, 4 in the Problem Solving forum “Take the task of creating a cricket team and break it into stages. Stage 1: Select 5 batsmen Since the order in which we select the batsmen does not matter, we can use combinations. We can select 5 batsmen from 7 batsmen in 7C5 ways (21 ways) So, we can complete stage 1 in 21 ways ...” March 29, 2019 Brent@GMATPrepNow posted a reply to What percentage of his bills did Stanley pay before their in the Data Sufficiency forum “Target question: What percentage of his bills did Stanley pay before their due dates last month? This is a great candidate for rephrasing the target question. Aside: We have a free video with tips on rephrasing the target question: Let P = # of bills PAID before due date Let T = TOTAL # of ...” March 29, 2019 Brent@GMATPrepNow posted a reply to If $$n$$ is a positive integer and $$r$$ is the remainder in the Data Sufficiency forum “ Given: r is the remainder when (n² - 1) is divided by 8 Target question: What is the value of r? Statement 1: n is odd Let''s test some ODD values of n If n = 1, then n² - 1 = 1² - 1 = 0, and 0 divided by 8 leaves remainder 0. So, the answer to the target question is r = 0 If n = 3, ...” March 29, 2019 Brent@GMATPrepNow posted a reply to If √k is not an integer, then is k a prime number? in the Data Sufficiency forum “ Given: √k is not an integer Target question: Is k a prime number? Statement 1: k < 10 Let''s TEST some values. There are several values of k that satisfy statement 1. Here are two: Case a: k = 1.3 (√1.3 is not an integer). In this case, the answer to the target question is NO, ...” March 29, 2019 Brent@GMATPrepNow posted a reply to The ratio of boys to girls in Class A is 3 to 4. The ratio in the Problem Solving forum “The ratio of boys to girls in Class A is 3 to 4. Let B = number of boys in class A Let G = number of girls in class A We get: B/G = 3/4 Cross multiply to get: 4B = 3G Class A has one more boy and two more girls than class B So B - 1 = number of boys in class B So G - 2 = number of girls in ...” March 29, 2019 GMATGuruNY posted a reply to A 3-character alpha-numeric code does have the following in the Problem Solving forum “Number of options for the first character = 8. (Of the 10 digits, any digit but 0 or 9.) Number of options for the second character = 24. (Of the 26 letters in the alphabet, any but a or z.) Number of options for the third character = (number of options for the first character) + (number of ...” March 29, 2019 GMATGuruNY posted a reply to The ratio of boys to girls in Class A is 3 to 4. The ratio in the Problem Solving forum “We can PLUG IN THE ANSWERS, which represent the number of girls in Class A. Since b:g = 3:4, the number of girls must be a multiple of 4. Eliminate B, C and D. Answer choice A: g = 8. Since b:g = 3:4 = 6:8, b=6. Since Class A has one more boy and two more girls than Class B, in Class B, ...” March 29, 2019 GMATGuruNY posted a reply to 100 students appeared for two tests-Maths and English. For in the Data Sufficiency forum “100 = Only Math + Only English + Both + Neither For every student who passed in both the tests, 8 students passed only in Maths and 9 students passed only in English. Let B = both, implying that Only Math = 8B and that Only English = 9B. Thus: 100 = 8B + 9B + B + Neither 100 = 18B + Neither ...” March 28, 2019 GMATGuruNY posted a reply to An optometrist charges$150 per pair for soft contact lenses in the Problem Solving forum
“Since $150 soft lenses and$85 hard lenses yield $1690 in revenue, we get: 150S + 85H = 1690 30S + 17H = 238 The sum on the left side must yield a units digit of 8. Since 17*4 = 68, it is likely that H=4: 30S + 17*4 = 338 30S + 68 = 238 30S = 170 S=9 S=9 and H=4 satisfy the condition ...” March 28, 2019 GMATGuruNY posted a reply to OG-12 SC Q-43 Laos has a land area in the Sentence Correction forum “D: Laos has a land area comparable to the size of Great Britain, but only four million in population, and many are members of hill tribes ensconced in the virtually inaccessible mountain valleys of the north. Error 1: The intent here is to compare the LAND AREA of Laos to the LAND AREA of Great ...” March 28, 2019 GMATGuruNY posted a reply to Which of the following is the solution set for the inequalit in the Problem Solving forum “We can PLUG IN THE ANSWERS, which represent the range of x. A: -1 < x < 0 Plugging x=-0.5 into the given inequality, we get: 0 < |-0.5| - 2(-0.5) < 3 0 < 0.5 + 1 < 3 0 < 1.5 > 3 Since x=-0.5 is a valid solution, the correct answer must include x=-0.5 within its ...” March 28, 2019 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Data Sufficiency lesson #5: - Summarizing Information Video : https://www.youtube.com/watch?v=cK9PR3SLsSA Cheers, Brent” March 27, 2019 Brent@GMATPrepNow posted a reply to The water from one outlet, flowing at a constant rate, can in the Problem Solving forum “So, let''s say that the volume of the pool is 45 gallons. The water from one outlet, flowing at a constant rate, can fill a swimming pool in 9 hours So, this outlet pumps at a rate of 5 gallons per hour The water from a second outlet, flowing at a constant rate, can fill the same pool in 5 ...” March 27, 2019 Brent@GMATPrepNow posted a reply to If a positive integer t is not divisible by 5, how many poss in the Problem Solving forum “Since t is NOT divisible by 5, we need only test t = 1, 2, 3 and 4 If t = 1, then t⁴ = 1, and 1 divided by 5 leaves remainder 1 If t = 2, then t⁴ = 16, and 16 divided by 5 leaves remainder 1 If t = 3, then t⁴ = 81, and 81 divided by 5 leaves remainder 1 If t = 4, then t⁴ = 256, and ...” March 27, 2019 Brent@GMATPrepNow posted a reply to At a certain school, the student to teacher ratio is 52 to 9 in the Problem Solving forum “There''s a nice integer properties rule that says: If j is a multiple of d, and k is NOT a multiple of d, then j-k (and j+k) is NOT a multiple of d For example, since 56 is a multiple of 7, and 11 is NOT a multiple of 7, then 56-11 is NOT a multiple of 7 At a certain school, the student to ...” March 27, 2019 GMATGuruNY posted a reply to A straight highway connects two cities P and Q, and goes via in the Data Sufficiency forum “Statement 1: For every 2 hours spent at 30 mph and 1 hour spent at 50 mph, 3 hours are spent at 60 mph. Average speed per 6 hours = (2*30 + 1*50 + 3*60)/6 = 290/6. SUFFICIENT. Statement 2: Case 1: NQ = 180 miles, PM = 60 miles and MN = 50 miles Since NQ is traveled at 60 mph, the time for ...” March 27, 2019 GMATGuruNY posted a reply to Geometry in the Problem Solving forum “https://i.postimg.cc/N2Ky6DSp/square-divided-into-triangles.png Each triangle in the figure above is an isosceles right triangle with sides 1, 1 and √2. Shaded region = 4 triangles. Largest square = 16 triangles. Thus: (shaded region)/(largest square) = 4/16 = 1/4. The correct answer is ...” March 27, 2019 Brent@GMATPrepNow posted a new topic called At a certain school, the student to teacher ratio is 52 to 9 in the Problem Solving forum “At a certain school, the student to teacher ratio is 52 to 9. If 38 students and 11 teachers leave, which of the following COULD represent the number of students and teachers remaining at the school? A) 532 students and 88 teachers B) 794 students and 162 teachers C) 1106 students and 225 ...” March 26, 2019 GMATGuruNY posted a reply to A music festival took place over two days, Saturday and in the Data Sufficiency forum “Anyone who attended the festival must have attended only Saturday, only Sunday, or both days. Let the total number of attendees = 100. Statement 1: 40% of attendees attended both days. No way to determine how many attendees attended only Saturday. INSUFFICIENT. Statement 2: 70% of attendees ...” March 26, 2019 GMATGuruNY posted a reply to Boat World sells a certain boat and a certain trailer. What in the Data Sufficiency forum “Let b = boat and t = trailer. What is the value of t? Statement 1: b = 7500+t No way to solve for t. INSUFFICIENT. Statement 2: b+t = 15000 No way to solve for t. INSUFFICIENT. Statements combined: Since we have two variables (b and t) and two distinct linear equations (b=7500+t and ...” March 26, 2019 GMATGuruNY posted a reply to p, q, and r are different prime numbers. What is the value o in the Data Sufficiency forum “Statement 1: (pq)² = 36 pq = 6 Case 1: p=2 and q=3 Case 2: p=3 and q=2 Since q can be different values, INSUFFICIENT. Statement 2: (qr)² = 225 qr = 15 Case 1: q=3 and r=5 Case 2: q=5 and r=3 Since q can be different values, INSUFFICIENT. Statements combined: Only one case ...” March 26, 2019 GMATGuruNY posted a reply to √r + 2/√r = 4. What is the value of r + 4/r? in the Problem Solving forum “(a+b)² = a² + b² + 2ab √r + 2/√r = 4 (√r + 2/√r)² = 4² (√r)² + (2/√r)² + 2(√r)(2/√r) = 16 r + 4/r + 4 = 16 r + 4/r = 12 The correct answer is A.” March 26, 2019 Brent@GMATPrepNow posted a reply to For all positive integers m in the Problem Solving forum “Thanks Roach! Cheers, Brent - now with 50% less "t"!!” March 25, 2019 GMATGuruNY posted a reply to How many trailing zeroes would be found in 63! upon in the Problem Solving forum “TRAILING 0''s = the number of 0''s at the end of a large product. 63! = 63*62*61*....*3*2*1. Since 10=2*5, EVERY COMBINATION OF 2*5 contained within the prime-factorization of 63! will yield a 0 at the end of the integer representation of 63!. The prime-factorization of 63! includes FAR ...” March 25, 2019 Brent@GMATPrepNow posted a reply to When f(x)=x^3+1/x3, which of the following is equal to f(-1/ in the Problem Solving forum “GIVEN: f(x)=x³ + 1/x³ So, f(-1/x) = (-1/x)³ + 1/(-1/x)³ = -1/x³ + 1/(-1/x³) = -1/x³ - x³ = -(1/x³ + x³) = -(x³ + 1/x³) = -f(x) Answer: B Cheers, Brent” March 25, 2019 Brent@GMATPrepNow posted a reply to Last year a certain bond with a face value of$5,000 yielded in the Problem Solving forum
“Last year a certain bond with a face value of $5,000 yielded 8 percent of its face value in interest 8% of$5,000 = $400 So, interest =$400 If that interest was approximately 6.5 percent of the bond''s selling price,approximately what was the bond''s selling price? Let x = the bond''s ...”
March 25, 2019
GMATGuruNY posted a reply to A certain NYC taxi driver has decided to start charging a in the Problem Solving forum
“Let r=100 cents. For 3 people, the cost per mile = 3*100 = 300 cents = 3 dollars. Let x = 2 miles. Regular cost for 3 people to travel 2 miles = 3*2 = 6 dollars. With a 50% discount, the cost in dollars = 3. This is our target. Now we plug x=2 and r=100 into the answers to see which ...”
March 25, 2019
GMATGuruNY posted a reply to 60% of all students in a class commute by public in the Problem Solving forum
“Use a DOUBLE-MATRIX to organize the data. Let P = public transportation, NP = not public transportation, S = science, NS = not science. 60% of all students in a class commute by public transportation. 30% of the students aspire to be scientists. The following matrix is yielded: ...”
March 25, 2019
GMATGuruNY posted a reply to GPREP SC-8 in the Sentence Correction forum
“Proposed revision: The sandpipers...are a result of residential and industrial development. This meaning is nonsensical. BIRDS cannot be a RESULT. This line of reasoning is valid: In D and E, the referent for in the northeastern United States is unclear.”
March 24, 2019
Brent@GMATPrepNow posted a reply to Is it true that x > 0? in the Data Sufficiency forum
“Target question: Is it true that x > 0? Statement 1: x² = 2x Rewrite as: x² - 2x = 0 Factor: x(x - 2) = 0 So, EITHER x = 0 OR x = 2 Let''s examine each possible case Case a: If x = 0, then the answer to the target question is NO, it is not true that x > 0 Case b: If x = 2, then ...”
March 24, 2019
GMATGuruNY posted a reply to If P and Q are positive integers, and if P > 1, does P = in the Data Sufficiency forum
“Statement 1: Case 1: P=2 and Q=2, with the result that P divides evenly into Q In this case, P=Q, so the answer to the question stem is YES. Case 2: P=2 and Q=4, with the result that P divides evenly into Q In this case, P≠Q, so the answer to the question stem is NO. INSUFFICIENT. ...”
March 24, 2019
GMATGuruNY posted a reply to Is it true that x > 0? in the Data Sufficiency forum
“Statement 1: Case 1: x=0 In this case, the answer to the question stem is NO. Case 2: x≠0, allowing us to divide both sides by x x²/x = 2x/x x = 2 In this case, the answer to the question stem is YES. INSUFFICIENT. Statement 2: Case 1: x=0 In this case, the answer to the question ...”
March 24, 2019
Brent@GMATPrepNow posted a reply to Problem with a practice question in the GMAT Math forum
“Here''s my full solution: https://www.beatthegmat.com/for-all-positive-integers-m-t299496.html Cheers, Brent”
March 23, 2019
GMATGuruNY posted a reply to Events A and B are independent and have equal probabilities in the Data Sufficiency forum
“Statement 1: P(at least one event occurs) = 1 - P(neither event occurs) Thus: P(at least A or B) = 1 - P(neither A nor B) Since P(at least A or B) = 0.84, we get: 0.84 = 1 - P(neither A nor B) P(neither A nor B) = 0.16 P(not A) * P(not B) = 0.16. Since it is given that P(A) = P(B), P(not ...”
March 23, 2019
GMATGuruNY posted a reply to In the given figure, if AS = 10 cm, SN = 5 cm and TN = 8 cm, in the Problem Solving forum
“Third-side rule: The third side a triangle must be LESS THAN THE SUM OF and GREATER THAN THE DIFFERENCE OF the other two sides. Here, all the sides must be INTEGER values. In triangle ANS, AS=10 and NS=5. Thus, third side AN must be an integer value less than 10+5 = 15 and greater than 10-5 = ...”
March 23, 2019
Brent@GMATPrepNow posted a reply to If $$xy \neq 0$$, and 75 percent of $$x$$ equals 125 percent in the Problem Solving forum
“GIVEN: 75 percent of x equals 125 percent of y Rewrite as: 3/4 of x = 5/4 of y Or we can say: (3/4)(x) = (5/4)( y) Multiply both sides by 4 to get: 3x = 5y Divide both sides by 5 to get: 3x/5 = y Rewrite as: y = (3/5)(x) Or y = 3/5 of x Or y = 60/100 of x Or y = 60% of x Answer: C ...”
March 22, 2019
Brent@GMATPrepNow posted a reply to If m and n are prime numbers, what is the value of m+n? in the Data Sufficiency forum
“ Given: m and n are prime numbers Target question: What is the value of m+n? Statement 1: 15 ≤ m < n ≤ 20 17 and 19 are the only PRIME numbers from 15 to 20 inclusive So, it must be the case that m = 17 and n = 19 So, the answer to the target question is m+n = 17 + 19 = 33 Since ...”
March 22, 2019
GMATGuruNY posted a reply to Express 2^20-2^19-2^18-2^17 as a power of 2. in the Problem Solving forum
“Test an analogous case with easier values: 2⁴ - 2³ - 2² - 2¹ = 16 - 8 - 4 - 2 = 2¹ The matching blue portions imply the following: 2²⁰ - 2¹⁹ - 2¹⁸ - 2¹⁷ = 2¹⁷ The correct answer is C.”
March 22, 2019