GMATGuruNY posted a reply to If 75 percent of the guests at a certain banquet ordered in the Data Sufficiency forum
“Let the total number of guests = 100. Since 75% of the guests ordered dessert, we get: Total desert = 0.75(100) = 75. Let C = total who ordered coffee. Let B = total who ordered both dessert and coffee. Statement 1: 60% of the guests who ordered dessert also ordered coffee. Thus: B = ...”
Today
GMATGuruNY posted a reply to Please explain in the Sentence Correction forum
“It must be crystal clear what a modifier is modifying. C: The computer company has announced that it will purchase the color-printing division of a rival company for $950 million, a part of a deal making it the largest manufacturer in the office color-printing market. Here, the intended ...”
Yesterday
GMATGuruNY posted a reply to <x> is the largest integer less than or equal to x and in the Problem Solving forum
“Let x = 0.5. < x > = <0.5> = the largest integer less than 0.5 = 0. A.”
July 17, 2018
GMATGuruNY posted a reply to Patrick purchased 80 pencils and sold them at a loss equa in the Problem Solving forum
“Since the two blue values above are equal, the given question stem is the same as the following: The cost of EACH PENCIL is how many times the selling price of EACH PENCIL? Let the selling price of each pencil = $1. Thus, the selling price of 80 pencils = $80. Since Patrick''s loss is equal ...”
July 17, 2018
GMATGuruNY posted a reply to If x < 12, then it must be true that in the Problem Solving forum
“If x=-100, then A, B and C are not true. If x=11, then D is not true. The correct answer is E. E: x-2 < 11 x < 13. Since the prompt indicates that x<12, x must be less than 13. Thus, E must be true.”
July 17, 2018
GMATGuruNY posted a reply to What is the probability that a 3-digit positive integer in the Problem Solving forum
“P(at least one 7) = 1 - P(no 7''s). P(no 7''s): P(hundreds digit is not 7) = 8/9. (Of the 9 possible digits that could serve as the hundreds digit, eight are not 7.) P(tens digit is not 7) = 9/10. (Of the 10 possible digits that could serve as the tens digit, nine are not 7.) P(units digit is ...”
July 17, 2018
GMATGuruNY posted a reply to There are 4 bottles with the same number balls in the Problem Solving forum
“Let the total number of balls = the sum of the parts of the final ratio = 1+6+5+4 = 16. Since there are 16 balls in total, and each of the 4 bottles begins with m balls, m=4. Since the number of balls in the first bottle decreases from 4 to 1, the number of balls moved from the first bottle = ...”
July 17, 2018
GMATGuruNY posted a reply to What is the mean number of defective pens in a box of pens? in the Data Sufficiency forum
“Statements combined: Since all the values are PERCENTS, there is no way to determine the average number of defective pens per box. Consider the following cases: Case 1: Each box contains 100 pens. Case 2: Each box contains 1,000,000 pens. Clearly, the average number of defective pens in Case 1 ...”
July 16, 2018
GMATGuruNY posted a reply to If t is the sum of three consecutive positive integers, is t in the Data Sufficiency forum
“Let the three consecutive integers be x, x+1 and x+2. Thus: t = x + (x+1) + (x+2) = 3x + 3 = 3(x+1). Statement 1: Since x = even, get get: t = 3(EVEN + 1) = ODD*ODD = ODD. An odd integer has no even factors. Since t is odd and thus has no even factors, it cannot be divisible by 24, which is ...”
July 16, 2018
GMATGuruNY posted a reply to Time and work problem in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent how many times a man''s output exceeds that of a woman. When the correct answer is plugged in, 3 men will take 5 fewer days to complete the job than 9 women. B: 4 Let the rate for each woman = 1 unit per day and the rate for each man = 4 units per ...”
July 16, 2018
GMATGuruNY posted a reply to In the rectangular coordinate system in the Data Sufficiency forum
“Statement 1: Thus, OP=12. Case 1: OQ=1, QS=1, and RS=12, with the result that the area of reach triangle = (1/2)(1)(12) = 6 In this case, R = (2, 12). Case 2: OQ=1, QS=12, and RS=1, with the result that the area of reach triangle = (1/2)(1)(12) = 6 In this case, R = (13, 1). Since R can have ...”
July 15, 2018
GMATGuruNY posted a reply to As envisioned by researchers, commercial farming of lobsters in the Sentence Correction forum
“A: to sell...standardize...and to predict D: to sell...take...and to predict E: to sell...take...to standardize...and to predict In each of these options, the verb form in red is not parallel with the surrounding infinitives in blue. Eliminate A, D and E. C: taking advantage of off-season ...”
July 14, 2018
GMATGuruNY posted a reply to Students in a class are arranged to form groups of 4 in the Data Sufficiency forum
“Let T = the total number of students. Since Statement 1 constrains T to a value less than 65, determine whether it''s possible that T<65 or that T≥65. Students in a class are arranged to form groups of 4 members each. After forming the groups, 3 students are left. Thus, T is equal to 3 ...”
July 14, 2018
GMATGuruNY posted a reply to doubt 2 in the Sentence Correction forum
“A: The protein in rice is higher quality. This wording implies that protein is a type of quality -- a nonsensical meaning. Eliminate A. Since the meaning is nonsensical, the comparison issue is moot.”
July 13, 2018
GMATGuruNY posted a reply to doubt 2 in the Sentence Correction forum
“Yes -- SC19 in the OG10.”
July 13, 2018
GMATGuruNY posted a reply to If a certain positive integer is divided by 9, the remainder in the Data Sufficiency forum
“Let x = the integer. If a certain positive integer is divided by 9, the remainder is 3. In other words, x is 3 more than a multiple of 9: x = 9a + 3 = 3, 12, 21, 30.... Statement 1: If the integer is divided by 45, the remainder is 30. In other words, x is 30 more than a multiple of 45: x = ...”
July 13, 2018
GMATGuruNY posted a reply to tricky odd/even integer question in the Data Sufficiency forum
“Statement 1: Test whether it''s possible that x is odd. Let x=1. Substituting x=1 into xy+z = ODD, we get: y+z = ODD Substituting x=1 into xy+xz = EVEN, we get: y+z = EVEN The equations in red contradict each other, implying that it is not possible that x is odd. Thus, x must be even. ...”
July 13, 2018
GMATGuruNY posted a reply to In a certain office, 50 percent of the employees are 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 red, we ...”
July 13, 2018
GMATGuruNY posted a reply to If a, b, and c are consecutive integers and a<b<c, is in the Data Sufficiency forum
“Case 1: a, b and c are EVEN-ODD-EVEN Case 2: a, b and c are ODD-EVEN-ODD Statement 1: Here, Case 2 is not possible: if a and c are both odd, then ac will be odd and thus not a multiple of 8. Since only Case 1 is possible, a must be even. SUFFICIENT. Statement 2: Case 1 is possible if a, b ...”
July 13, 2018
GMATGuruNY posted a reply to If the sequence {An } satisfies An = An-1 - An-2, A1 = 0, an in the Problem Solving forum
“A₁ = 0. A₂ = 1. A₃ = A₂ - A₁ = 1 - 0 = 1. A₄ = A₃ - A₂ = 1 - 1 = 0. A₅ = A₄ - A₃ = 0 - 1 = -1. A₆ = A₅ - A₄ = -1 - 0 = -1. A₇ = A₆ - A₅ = -1 - (-1) = 0. A₈ = A₇ - A₆ = 0 - (-1) = 1. The alternating blue and red implies the following pattern: 0, 1, ...”
July 12, 2018
July 11, 2018
GMATGuruNY posted a reply to Each of three charities in Novel Grove Estates has 8 persons in the Problem Solving forum
“This problem involves 3 overlapping sets: Charity A, Charity B, and Charity C. To organize the data, use a Venn Diagram: https://preview.ibb.co/fuXOMo/ABC_0.png Start in the CENTER and work outwards. Exactly 4 persons serve on 3 boards each. Inserting 4 people into the center of the ...”
July 11, 2018
GMATGuruNY posted a reply to Challenge: If line k passes through the points (48, 33) and in the Problem Solving forum
“Slope = ∆y/∆x = (33-22)/(48-31) = 11/17. Since (x, 0) and (31, 22) must yield the same slope, we get: (0-22)/(x-31) = 11/17 (x-31)(11) = (17)(-22) x - 31 = (17)(-2) x - 31 = -34 x = -3. The correct answer is B.”
July 11, 2018
GMATGuruNY posted a reply to If gcd(m,n) is the greatest common divisor of m and n, then in the Data Sufficiency forum
“Statement 1: Case 1: m=1 and n=1, with the result that gcd(m,n)=gcd(1,1)=1 Case 2: m=2 and n=2, with the result that gcd(m,n)=gcd(2,2)=2 Since n can be different values, INSUFFICIENT. Statement 2: Case 1: m=30 and n=30, with the result that gcd(m,n)=gcd(30,30)=30 and ...”
July 11, 2018
GMATGuruNY posted a reply to The terms of the sequence {An} satisfy A2 - A1 = 2, A3 - A2 in the Problem Solving forum
“Let n=3. According to the blue portion above, An+1 - An = A4 - A3 = 10. The correct answer must yield a result of 10 when n=3. Only B works: n² + 1 = 3² + 1 = 10. The correct answer is B.”
July 11, 2018
GMATGuruNY posted a reply to When the positive integer n is divided by 8, the remainder i in the Problem Solving forum
“When the positive integer n is divided by 8, the remainder is 3. In other words, n is 3 more than a multiple of 8: n = 8a + 3, where a is nonnegative integer. Options for n: 3, 11, 19, 27... When n is divided by 5, the remainder is 2. In other words, n is 2 more than a multiple of 5: n = 5b ...”
July 10, 2018
GMATGuruNY posted a reply to |m-n|=? in the Data Sufficiency forum
“{m-n| = the distance between m and n. Question stem, rephrased: What is the distance between m and n? Statement 1: Clearly INSUFFICIENT. Statement 2: Case 1: m=13 and n=1, with the result that the distance between m and n is 12 Case 2: m=100 and n=13/100, with the result that the distance ...”
July 10, 2018
GMATGuruNY posted a reply to The average age of a class of 10 students is 15. in the Problem Solving forum
“Alternate approach: Since the average age of the 10 original students = 15, the sum of the original 10 ages = (count)(average) = 10*15 = 150. One year later, each of the 10 students is 1 year older, increasing the sum of the ages by a total of 10 years: 150+10 = 160. After the addition of a ...”
July 9, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 Biologists with a predilection in the Critical Reasoning forum
“Passage: We must be open to the possibility that there are living things on other planets. Therefore, we will not be successful in defining what it is that makes something a living thing merely by examining living things on Earth. The statement in blue suggests the following: We cannot define an ...”
July 8, 2018
GMATGuruNY posted a reply to If x is an integer and y=3x+2, which of the following CANNOT in the Problem Solving forum
“Rule: MULTIPLE OF K + MULTIPLE OF K = MULTIPLE OF K MUTIPLE OF K + NON-MULTIPLE OF K = NON-MULTIPLE OF K y = 3x + 2 = MULTIPLE OF 3 + NON-MULTIPLE OF 3 = NON-MULTIPLE OF 3. Since y is not a multiple of 3, it cannot be a multiple of 6. The correct answer is C.”
July 8, 2018
GMATGuruNY posted a reply to Is the United States Singular or plural? in the Sentence Correction forum
“United States is singular. The OA employs the COMMAND SUBJUNCTIVE. The structure of the command subjunctive is BOSSY WORD + THAT + NOUN + BARE INFINITIVE. A bossy word serves to express a command or recommendation: requires, suggests, recommends, insists, etc. The bare infinitive is the ...”
July 8, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 (1/2 - 1/3) + (1/3-1/4) in the Problem Solving forum
“All the values between the first term and the last term CANCEL OUT. If we subtract the last term from the first term, we get: $$\ \frac{1}{2}-\frac{1}{6}=\ \frac{3}{6}-\frac{1}{6}=\frac{2}{6} = \frac{1}{3}$$ The correct answer is C.”
July 8, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 If S = 1 + in the Problem Solving forum
“BALLPARK. After the first four terms, the values are so small that they can be ignored. Approximate the sum of the first four terms: $$If\ S\ ≈\ 1\ +\ \frac{1}{4}+\frac{1}{10}+\frac{1}{15} = \ 1\ +\ \frac{15}{60}+\frac{6}{60}+\frac{4}{60} = \ 1\ +\ \frac{25}{60}$$ The resulting sum ...”
July 8, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 Over the past ten years in the Sentence Correction forum
“In B and C, second in importance is redundant. X is second to Y means -- all on its own -- that X is less important than Y. Eliminate B and C. Modifiers such as only and almost are known as LIMITERS. A limiter serves to LIMIT the scope of another word in the sentence. Generally, a limiter ...”
July 7, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 Many utilities obtain most of in the Sentence Correction forum
“In A, B, and D, higher as is unidiomatic. Correct: X is higher THAN Y Eliminate A, B and D. E: between two to three Here, between...to is unidiomatic. Correct: between X AND Y Eliminate E. The correct answer is C.”
July 7, 2018
GMATGuruNY posted a reply to In the x-y plane, y = f(x) = ax^2+bx+c passes through (1,0) in the Data Sufficiency forum
“f(x) = ax²+bx+c will be a U-shaped parabola if a>0. f(x) = ax²+bx+c will be a ∩-shaped parabola if a<0. Since f(x) = ax²+bx+c has x-intercepts at (1, 0) and (2, 0), f(3)>0 if the parabola is U-shaped. Question stem, rephrased: Is the parabola U-shaped? Statement 1: Since ...”
July 6, 2018
GMATGuruNY posted a reply to John invested 1/4 of A dollars in an investment fund, and pl in the Problem Solving forum
“Let A=40. Since John invests 1/4 of his money in the fund, the amount invested in the fund = (1/4)(40) = 10. Since the remainder is placed in the savings account, the amount placed in the savings account = 40−10 = 30. Since 4p = 4∗10 = 40%, John loses 40% of his $10 investment in the ...”
July 6, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 In a set of 24 cards, each in the Problem Solving forum
“P = (good outcomes)/(all possible outcomes) All possible outcomes: Since there are 24 cards, there are 24 possible outcomes. Good outcomes: For a number to be divisible by 2 and 3, it must be a multiple of 6. Multiples of 6 between 1 and 24, inclusive: 6, 12, 18, 24 For a number to be ...”
July 6, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 Which of the following is closest in the Problem Solving forum
“$$\sqrt{\frac{4.2\left(1,590\right)}{15.7}}$$ $$\sqrt{\frac{4\left(1600\right)}{16}}$$ $$\sqrt{\frac{1600}{4}}$$ $$\sqrt{400}$$ $$20$$ The correct answer is A.”
July 6, 2018
GMATGuruNY posted a reply to If positive integer p divided by 9 leaves a remainder of 1 in the Problem Solving forum
“Since dividing p by 9 yields a remainder of 1, p is ONE MORE THAN MULTIPLE OF 9: p = 9a + 1, where a is a nonnegative integer. Options for p 1, 10, 19, 28... If p=1, then Statement I is not true. Eliminate A, D and E. If p=10, then Statement II is not true. Eliminate B. The correct ...”
July 5, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 If n is an integer, what in the Data Sufficiency forum
“Statement 1: 12n = 432. Since we can solve for n, the GCF of 12 and n can be determined. SUFFICIENT. Statement 2: 24 = 2*2*2*3. Since the GCF of n and 24 is the blue product (12) without the red factor (2), n must be a multiple of 12 that does NOT include an additional factor of 2. In ...”
July 5, 2018
GMATGuruNY posted a reply to |x-y|=? in the Data Sufficiency forum
“Statement 1: Clearly INSUFFICIENT. Statement 2: If x=5 and y=1, then |x-y| = |5-1| = 4. If x=10 and y=0.5, then |x-y| = |10-0.5) = 9.5. Since |x-y| can be different values, INSUFFICIENT. Statements combined: If x=5 and y=1, then |x-y| = |5-1| = 4. If x=1 and y=5, then |x-y| = |1-5| = 4. ...”
July 4, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 The table shows partial results in the Problem Solving forum
“Percent who indicated coupons or store displays = 22+18 = 40. Total percent surveyed = 35+22+18+15 = 90. Resulting fraction: 40/90 = 4/9. The correct answer is D.”
July 4, 2018
GMATGuruNY posted a reply to If f(x) = 4x^2 + px, what is the minimum value of f(x)? in the Data Sufficiency forum
“To determine the minimum value of the graph, we need to know the value of p. Question stem, rephrased: What is the value of p? Statement 1: Substituting x=1 and f(x)=−4 into f(x) = 4x² + px, we get: -4 = 4(1)² + p(1) Since we can solve for p, SUFFICIENT. Statement 2: Substituting ...”
July 4, 2018
GMATGuruNY posted a reply to Which of the following equations has a graph that can pass t in the Problem Solving forum
“Eliminate the four answer choices with MORE THAN ONE coordinate pair (x, y ) such that x and y are integers. If x=1, integer values for y are yielded by A, C, D and E. If x=-1, integer values for y are yielded by A, C, D and E. Since each of these options has more than one coordinate pair (x, y ) ...”
July 3, 2018
GMATGuruNY posted a reply to If n is positive integer, is 21 a factor of n? in the Data Sufficiency forum
“Statement 1: In other words, 3n is a multiple of 21: 3n = 21, 42, 63... To get a list of options for n, divide every value above by 3: n = 7, 14, 21... If n=7, then the answer to the question stem is NO. If n=21, then the answer to the question stem is YES. INSUFFICIENT. Statement 2: ...”
July 3, 2018
GMATGuruNY posted a reply to OG SC question #171 "so as to vs so that" in the Sentence Correction forum
“Please see my explanation: https://www.beatthegmat.com/gmat-og-2019-technically-a-quicksanda-is-the-term-t302953.html”
July 2, 2018
GMATGuruNY posted a reply to GMAT OG 2019 Technically, “quicksand” is the term in the Sentence Correction forum
“I received a PM requesting that I explain why A is wrong. There are several reasons to eliminate A and choose B. so X as to Y implies that Y SEEMS TO BE TRUE. Official examples: Climatic shifts are so gradual as to be indistinguishable from ordinary fluctuations in the weather. The features ...”
July 2, 2018
GMATGuruNY posted a reply to If a rectangular box has two faces with an area of 30 in the Problem Solving forum
“Nice approach. Just one suggestion: Rather than calculate the product of 60, 30 and 72, break the factors into perfect squares, as follows: V² = 30 * 60 * 72 V² = 30 * 30 * 2 * 2 * 36 V = √(30*30) * √(2*2) * √(6*6) V = 30*2*6 = 360.”
July 2, 2018
GMATGuruNY posted a reply to n=? in the Data Sufficiency forum
“Statement 1: Case 1: n=1, with the result that n² = 1² = 1 Case 2: n=-1, with the result that n² = (-1)² = 1 Since n can be different values, INSUFFICIENT. Statement 2: Here, the only one option for n is possible: n=1. SUFFICIENT. The correct answer is B.”
July 2, 2018
GMATGuruNY posted a reply to A certain company employs 6 senior officers and 4 junior in the Problem Solving forum
“From 6 senior officers, the number of ways to choose 3 for the committee = 6C3 = (6*5*4)/(3*2*1) = 20. Since there are 4 junior officers, the number of options for the junior officer on the committee = 4. To combine the options above, we multiply: 20*4 = 80. The correct answer is D.”
July 2, 2018
GMATGuruNY posted a reply to Jamshid can paint a fence in 50 percent less time than in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent Taimour''s time alone. Since Jamshid and Taimour working together takes 8 hours to paint the fence, Taimour''s time alone must be more than 8 hours. Eliminate A and B. When the correct answer is plugged in, Jamshid''s time alone will be 50% less than ...”
July 2, 2018
GMATGuruNY posted a reply to If z^n = 1, what is the value of z? in the Data Sufficiency forum
“Statement 1: Case 1: z=1 and n=1, with the result that z^n = 1¹ = 1 Case 2: z=-1 and n=2, with the result that z^n = (-1)² = 1 Since z can be different values, INSUFFICIENT. Statement 2: Case 1: z=1 and n=1, with the result that z^n = 1¹ = 1 Case 2: z=2 and n=0, with the result that z^n = ...”
July 2, 2018
GMATGuruNY posted a reply to If a rectangular box has two faces with an area of 30 in the Problem Solving forum
“Let LW = 72 such that L=6 and W=12. Since the other two given areas are 30 and 60, H=5: LH = 6*5 = 30. WH = 12*5 = 60. Thus: V = LWH = 6*12*5 = 360. The correct answer is E.”
July 2, 2018
GMATGuruNY posted a reply to What is the remainder when 1044*1047*1050*1053 is in the Problem Solving forum
“This problem is beyond the scope of the GMAT. Feel free to ignore it.”
July 2, 2018
GMATGuruNY posted a reply to A shelf contains only books of poetry, short stories, in the Data Sufficiency forum
“Neither statement alone offers any information about the number of nonfiction books. Statements combined: Number of nonfiction books = (total number of books) - (poetry books) - (short story books) = 15 -4-5 = 6. Since 6 of the 15 books are nonfiction, we get: P(selecting a nonfiction book) = ...”
July 2, 2018
GMATGuruNY posted a reply to Challenge question: If j and k are positive integers, and (k in the Problem Solving forum
“Options for j such that j⁶ will divide into 29²⁹11¹¹: j=1 j=11 j=29 j=29² j=29³ j=29⁴ j=11*29 j=11*29² j=11* 29³ j=11*29⁴ Since there are 10 options for j, there are 10 options for k. The correct answer is B.”
July 1, 2018
GMATGuruNY posted a reply to Thomas Eakins' powerful style-The present perfect tense coul in the Sentence Correction forum
“The rule to which you are referring is discussed at length in my posts here: https://www.beatthegmat.com/comparison-t289039-15.html This rule is applicable only when the adjective in each clause is THE SAME: Its numbers are now five times greater than great] when the use of DDT was sharply ...”
July 1, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 From 2000 to 2003, the number in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the number of employees in 2000. Since the number of employees increases by 1/4 and then decreases by 1/3, the correct answer must be divisible by 4 and 3. In other words, the correct answer must be a MULTIPLE OF 12. Eliminate A, C and D. Since the ...”
July 1, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 Last year $48,000 of a in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the share for each owner. Since the share for each owner is 3 times the share for each employee, the correct answer is almost certainly a multiple of 3 (A, B, C or E). When the correct answer is plugged in, the total profit = 48,000. B: $9000 for each ...”
July 1, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 Robin invested a total of $12,000 in the Data Sufficiency forum
“Since X and Y constitute a total investment of $12,000, we get; X + Y = 12,000 Statement 1: Since 3% of X must yield the same amount of interest as 6% of Y, we get: 0.03X = 0.06Y Since we have two variables (X and Y) and two distinct linear equations (X+Y=12000 and 0.03X=0.06Y), we can solve ...”
June 30, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 If x is a positive integer in the Problem Solving forum
“Subtract 3 from increasing powers of 4: 4¹ - 3 = 1 4² - 3 = 13 The results above indicate that the following case is not possible: $$4^x - 3 = 7$$ The correct answer is B.”
June 30, 2018
GMATGuruNY posted a reply to If Alice traveled on a 10 km trip at a constant speed of 25 in the Problem Solving forum
“Since Alice travels only a small portion of the total distance at 25 kph but the vast majority of the entire distance at 30 kph, her average speed for the entire trip must be just a bit less than 30 kph. Of the five answer choices, only C is sufficiently close to 30 kph. The correct answer is C.”
June 29, 2018
GMATGuruNY posted a reply to A cashier mentally reversed the digits of one customer's in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the correct amount of change. When the digits in the correct answer are reversed, the resulting integer must yield a decrease of 45 cents -- the 45 cents left in the register by mistake. Since reversing the digits must yield a decrease of 45 cents, the ...”
June 28, 2018
GMATGuruNY posted a reply to Tom, who has 50 math questions, will get 5 points in the Problem Solving forum
“Since each question is worth 5 points, a perfect score on the 50-question test = 50*5 = 250. For every question missed, Tom will forgo the 5 points attributed to the question and will lose another 2 points for missing the question, for a net loss of 7 points per missed question. Thus, Tom''s score ...”
June 28, 2018
GMATGuruNY posted a reply to Of the integers between 100 and 799, inclusive in the Problem Solving forum
“Number of options for the hundreds digit = 5. (Of the seven digits 1-7, any but 2 or 5.) Number of options for the tens digit = 8. (Of the ten digits 0-9, any but 2 or 5.) Number of options for the units digit = 8. (Of the ten digits 0-9, any but 2 or 5.) To combine these options, we multiply: ...”
June 28, 2018
GMATGuruNY posted a reply to What is the greatest possible (straight line) distance in the Problem Solving forum
“The longest line that can be drawn inside a rectangular solid is called the MAIN DIAGONAL. Use the SUPER-PYTHAGOREAN THEOREM. If d = the length of the main diagonal, then: d² = l² + w² + h². In the problem above: d² = 10² + 10² + (0.1)² d² = 100 + 100 + 0.01 d² = 200.01 ...”
June 28, 2018
GMATGuruNY posted a reply to 3^n+3^{n+1}+3^{n+2}/3^{n-2}+3^{n-1}+3^n=? in the Problem Solving forum
“Both C and D yield a value of 3² when n=2. As a result, a test-taker would have to test another case to determine whether the correct answer is C or D. When plugging in values, we should avoid numbers that appear in the answer choices. Here -- since 2 appears in the answer choices -- we should ...”
June 28, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 [What was the median annual] in the Data Sufficiency forum
“The median salary is equal to the 15th highest salary. When the statements are combined, the 15th highest salary can be any positive value. Thus, the two statements combined are INSUFFICIENT. The correct answer is E.”
June 28, 2018
GMATGuruNY posted a reply to GMAT Official Guide 2019 [What is the number of] in the Data Sufficiency forum
“Statements combined: It''s possible that the article is composed of two 5.5 by 8 pages, each with 250 words. It''s possible that the article is composed of three 5.5 by 8 pages, each with 250 words. Since the number of pages can be different values, the two statements combined are INSUFFICIENT. ...”
June 28, 2018
GMATGuruNY posted a reply to A set of pictures of butterflies contains 10 pictures. in the Problem Solving forum
“P(1st picture selected has not already been purchased) = 7/10. (Of the 10 pictures, 3 have already been purchased, so 7 have not.) P(2nd picture selected has not already been purchased) = 6/9. (Of the 9 remaining pictures, 3 have already been purchased, so 6 have not.) To combine these ...”
June 28, 2018
GMATGuruNY posted a reply to Allison and Barbara are part of an 8-member dance troupe. in the Problem Solving forum
“There are 7 people besides Allison. From this pool of 7 people, 3 must be selected to join Allison''s 4-person ensemble. Thus -- from the pool of 7 people -- the probability that Barbara is among the 3 people selected = 3/7. The correct answer is B.”
June 27, 2018
GMATGuruNY posted a reply to The relationship between the cost (c) and time (t) is given in the Data Sufficiency forum
“Original cost = mt+ b. When the time increases by 10, we get: New cost = m(t+10) + b = mt + 10m + b. Thus: Increase in the cost = new cost - original cost = (mt + 10m + b) - (mt + b) = 10m. To determine the increase in the cost, we need to know the value of m. Question stem, rephrased: What ...”
June 27, 2018
GMATGuruNY posted a reply to If An+1=120 + (1/4)An for each positive integer n, and A1=15 in the Problem Solving forum
“A₂ = 120 + (1/4)(A₁) = 120 + (1/4)(150) = 120 + 37.5 = 157.5. A₃ = 120 + (1/4)(A₂) = 120 + (1/4)(157.5) ≈ 120 + 39 = 159. A₄ = 120 + (1/4)(A₃) = 120 + (1/4)(159)... The results above indicate that the terms are increasing in value. Thus, A₁₂ > 159. The correct answer is ...”
June 27, 2018
GMATGuruNY posted a reply to At a fruit store, apples are sold for $4 per pound and orang in the Data Sufficiency forum
“Statement 1: The average price-per-pound for the MIXTURE of apples and oranges (less than $5) is closer to the price-per-pound for apples ($4) than to the price-per-pound for oranges ($6). Implication: Weight-wise, the mixture must be composed mostly of apples. Thus, the answer to the question ...”
June 26, 2018
GMATGuruNY posted a reply to 3^n+3^{n+1}+3^{n+2}/3^{n-2}+3^{n-1}+3^n=? in the Problem Solving forum
“Let n = 3. Plugging n = 3 into the given expression, we get: $$\frac{3^3+3^{3+1}+3^{3+2}}{3^{3-2}+3^{3-1}+3^3}\\$$ $$\frac{3^3+3^4+3^5}{3^1+3^2+3^3}\\$$ $$\frac{3^3(1 + 3 + 3^2)}{3(1+3+3^2)} = 3^2\\$$ When n=3 is plugged into the answers, the result must be 3². Only D is viable. ...”
June 26, 2018
GMATGuruNY posted a reply to Bob and Alice can finish a job together in 3 hours. in the Problem Solving forum
“Let the job = the LCM of the two times = 15 units. Since Bob and Alice together take 3 hours to produce the job, their combined rate = w/t = 15/3 = 5 units per hour. Since Bob on his own takes 5 hours to produce the job, Bob''s rate = w/t = 15/5 = 3 units per hour. Since Bob and Alice together ...”
June 26, 2018
GMATGuruNY posted a reply to Alice and Bob drive the same car. Alice drives the car for 1 in the Problem Solving forum
“The prompt should specify that 1/4 of the trip = 1/4 of the total distance. We can PLUG IN THE ANSWERS, which represent the total distance. When the correct answer is plugged in, the difference between Bob''s distance and Alice''s distance = 40 km. B: 80 km Alice''s distance = (1/4)(80) ...”
June 25, 2018
GMATGuruNY posted a reply to How long did Justin spend driving from Town A to Town B in the Data Sufficiency forum
“Each statement is clearly insufficient on its own. Statements combined: Distance from A to B = (total distance) - (distance from B to C) = 200-100 = 100 miles. The time to travel from A to B can be ANY POSITIVE VALUE. Thus, the total time for the entire trip cannot be determined. INSUFFICIENT. ...”
June 25, 2018
GMATGuruNY posted a reply to Is wp + st > 0? in the Data Sufficiency forum
“Statements combined: Try to satisfy both statements while making wp POSITIVE. Case 1: w=p=s=t=1, with the result that ws + pt = ws + pt = (1*1) + (1*1) = 2 and that wt + ps = (1*1) + (1*1) = 2 In this case, wp + st = (1*1) + (1*1) = 2, so the answer to the question stem is YES. Try to ...”
June 25, 2018
GMATGuruNY posted a reply to If P is an odd integer and (P^2 + Q * R) is an even integer, in the Problem Solving forum
“Let P=1. Case 1: (P² + QR) = 2 Plugging P=1 into the equation above, we get: 1² + QR = 2 QR = 1. If Q=1 and R=1, then B and D are not true. Eliminate B and D. If Q=2 and R=1/2, then A and C is not true. Eliminate A and C. The correct answer is E.”
June 25, 2018
GMATGuruNY posted a reply to What is the value of prime number z? in the Data Sufficiency forum
“Statement 1: z³ < 25 Only one value for z is possible: z = 2, with the result that z³ = 2³ = 8. If z is any other prime number, the value of z³ will exceed 25. Thus, z=2. SUFFICIENT. Statement 2: z² > 1 Here, z can be ANY PRIME NUMBER, since the square of any prime number will be ...”
June 25, 2018
GMATGuruNY posted a reply to A car averages 55 mph for the first 4 hours of a trip in the Problem Solving forum
“Since the car travels at 55 mph for 4 hours, the distance traveled in the first 4 hours = rt = 55*4 = 220 miles. We can PLUG IN THE ANSWERS, which represent the total time. When the correct answer is plugged in, the average speed for the whole trip = 60 mph. B: 8 hours, implying that the last 4 ...”
June 25, 2018
GMATGuruNY posted a reply to If x and y are integers, is 5x + y divisible by 5? in the Data Sufficiency forum
“Statement 1: Case 1: x=5 and y=0 In this case, 5x + y = (5*5) + 0 = 25, so the answer to the question stem is YES. Case 2: x=5 and y=1 In this case, 5x + y = (5*5) + 1 = 26, so the answer to the question stem is NO. Since the answer is YES in Case 1 but NO in Case 2, INSUFFICIENT. Statement ...”
June 25, 2018
GMATGuruNY posted a reply to In a sequence of 40 numbers, each term, except for in the Problem Solving forum
“Since each term is 7 less than the preceding term, the numbers are EVENLY SPACED. For any evenly spaced set, where d is the distance between successive terms: $$a_{n} = a_{1} - (n-1)d$$ In the problem above: a₄₀ = ? a₁ = 281 n = 40 Since each term is 7 less than the preceding term, d ...”
June 25, 2018
GMATGuruNY posted a reply to In a certain class, boys' heights range is 10 inches, and in the Data Sufficiency forum
“Since the range for the boys = 10, we get: tallest boy - shortest boy = 10 tallest boy = 10 + shortest boy. Since the range for the girls = 8, we get: tallest girl - shortest girl = 8 shortest girl = tallest girl - 8. Statement 1: Case 1: tallest girl = 10, shortest boy = 12 Substituting ...”
June 24, 2018
GMATGuruNY posted a reply to With California expected to see severe electricity shortfall in the Sentence Correction forum
“to facilitate X = to make it easier for X to happen. An introductory with-modifier serves to express something that facilitates the action the in the following clause. OA: With California expected to see severe electricity shortfalls and perhaps blackouts on as many as 30 days this summer, the ...”
June 22, 2018
GMATGuruNY posted a reply to A shelf contains hardcover and paperback books, of either in the Data Sufficiency forum
“This is an EITHER/OR group question. Every book is EITHER hardcover OR paperback. Every book is EITHER fiction OR nonfiction. For an EITHER/OR group problem, use a DOUBLE-MATRIX to organize the data. There are two fractions in statement 1: 2/3 and 1/4. Since the product of the denominators = ...”
June 22, 2018
GMATGuruNY posted a reply to A marzipan factory has two machines producing marzipan. in the Data Sufficiency forum
“Let N = 4 kg and D''s time for N kg = 1 hour. Thus, D''s rate = (4 kg)/(1 hour) = 4 kg per hour. Since W produces N/2 kg (2 kg) in twice D''s time for N kg (2 hours), W''s rate = (2 kg)/(2 hours) = 1 kg per hour. Combined rate for D+W = 4+1 = 5 kg per hour. Of every 5 kg produced each hour ...”
June 22, 2018
GMATGuruNY posted a reply to A jar contains exactly 100 marbles; each marble contains in the Data Sufficiency forum
“To calculate the probability of picking at least 2 marbles that contain no blue, we need to know how many of the 100 marbles are part-blue. Question stem, rephrased: How many of the 100 marbles are part-blue? Total marbles = (total part-green) + (total part-red) + (total part-orange) + (total ...”
June 21, 2018
GMATGuruNY posted a reply to When a, b and c are consecutive positive even integers such in the Problem Solving forum
“Test a=6, b=4 and c=2 in the five answer choices. Eliminate any answer choice that does not yield an odd integer. A: (a-c)/2 = (6-2)/2 = 2 --> Eliminate A. B: (a-c)/2 = (2-6)/2 =- 2 --> Eliminate B. C: (a+c)/2 = (6+2)/2 = 4 --> Eliminate C. D: (a+c)/4 = (6+2)/4 = 2 --> Eliminate ...”
June 21, 2018
GMATGuruNY posted a reply to Between 1980 and 1985, Pierre’s investment portfolio in the Data Sufficiency forum
“Let the original investment = $100. Question stem, rephrased: Is the current value greater than $100? Case 1: z=100% Implication: After 1990, Pierre loses 100% of his investment, reducing its value to $0. In this case, x and y are irrelevant. The answer to the rephrased question stem is ...”
June 20, 2018
GMATGuruNY posted a reply to A house cost Ms. Jones C dollars in 1965. Three years in the Problem Solving forum
“Since 25% = 1/4 and 50% = 1/2, let C = the LCM of the two denominators = 4*2 = 8. Since Ms. Jones sells the house for 25% above cost, her profit is equal to 1/4 of the cost: (1/4)(8) = 2. Since she must pay a tax equal to 50% of her profit, the tax = (1/2)(2) = 1. Now plug C=8 into the answers ...”
June 20, 2018
GMATGuruNY posted a reply to If x and y are positive integers such that x^2+y^2 in the Data Sufficiency forum
“Perfect squares less than 18: 1, 4, 9, 16. Perfect cubes less than 18: 1, 8. Options for x²+y³ such that the sum is prime: 1+1 = 2, implying that x=1 and y=1. 4+1 = 5, implying that x=2 and y=1. 9+8 = 17, implying that x=3 and y=2. 16+1 = 17, implying that x=4 and y=1. Both statements ...”
June 20, 2018
GMATGuruNY posted a reply to If the product of 5 different positive integers is less than in the Problem Solving forum
“To MAXIMIZE the largest integer, MINIMIZE the other four integers. Since the integers must be positive and distinct, the smallest possible option for the other four integers is as follows: 1*2*3*4 = 24. We can PLUG IN THE ANSWERS, which represent the value of the largest integer. Of the five ...”
June 20, 2018
GMATGuruNY posted a reply to Aqaba Jordan OG16 in the Sentence Correction forum
“The new bridge will cost $100 million, as the city planner indicates in next year''s budget proposal. Here, indicates is logically preceded by its subject (the city planner). A ruined structure was probably a church, as indicates its eastward orientation and overall plan. Here, the intended ...”
June 19, 2018
GMATGuruNY posted a reply to three-digit code in the Problem Solving forum
“Case 1: 2nd digit is 0 Number of options for the 3rd digit = 9. (Any digit but 0, since the 2nd and 3rd digits cannot both be 0.) Number of options for the 1st digit = 8. (Any digit but 0 or 1.) To combine these options, we multiply: 9*8 = 72. Case 2: 2nd digit is 1 Number of options for the ...”
June 19, 2018
GMATGuruNY posted a reply to If n >2 and n^4-5n^2+4 = 20h, Is h an integer? in the Data Sufficiency forum
“n⁴ - 5n² + 4 = 20h (n²-4)(n²-1) = 20h (n+2)(n-2)(n+1)(n-1) = 20h h will be an integer if the left side is equal to a MULTIPLE OF 20. Question stem, rephrased: Is (n+2)(n-2)(n+1)(n-1) a multiple of 20? Statement 1: Test one case that also satisfies Statement 2. Case 1: n=20, with ...”
June 18, 2018
June 18, 2018
GMATGuruNY posted a reply to gmat prep q in the Problem Solving forum
“Let x=y=1. Then: 2^(x+y)² / 2^(x-y)² = 2^(1+1)² / 2^(1-1)² = 2⁴/2⁰ = 16/1 = 16. The correct answer is D.”
June 18, 2018
GMATGuruNY posted a reply to What is the units digit of 248^20? in the Problem Solving forum
“When 8 is raised to consecutive powers, the unit digit repeat in a CYCLE OF 4: 8¹ --> units digit of 8. 8² --> units digit of 4. (Since the product of the preceding units digit and 8 = 8*8 = 64.) 8³ --> units digit of 2. (Since the product of the preceding units digit and 8 = 4*8 = ...”
June 18, 2018
GMATGuruNY posted a reply to The size of a television screen is given as the length in the Problem Solving forum
“We can save a little time if we know the following: The area of a rhombus with diagonals d₁ and d₂ = (d₁d₂)/2. A square is a rhombus with 4 equal angles. In a square, the two diagonals are equal. Thus, the area of a square with diagonal d = d²/2. a² - b² = (a+b)(a-b). ...”
June 18, 2018
GMATGuruNY posted a reply to A sales associate earns a commission of 8% on in the Data Sufficiency forum
“Initial commission = 8% of 10,000 = $800. Let x = the sales amount after the first $10,000. Additional commission = 10% of sales amount after the first $10,000 = (1/10)x. To calculate the total sales, we need to know the value of x. Question stem, rephrased: What is the value of x? Statement ...”
June 18, 2018
GMATGuruNY posted a reply to If x and y are positive integers and n = 5^x + 7^(y + 3) in the Data Sufficiency forum
“5^x will have a units digit of 5, regardless of the value of x: 5¹ = 5 5² = 25 5³ = 125 In every case, the units digit is 5. To determine the units digit of n, we need to know the units digit of 7^(y+3). Question stem, rephrased: What is the units digit of 7^(y+3)? When 7 is raised to ...”
June 18, 2018
GMATGuruNY posted a reply to If |x - 2| = |x + 3|, x could equal in the Problem Solving forum
“The warning above must be heeded when only one side of an equation is an absolute value. But when BOTH sides of an equation are absolute values, any solution that we derive will be guaranteed to work, so the step above is unnecessary. Since both sides of |x - 2| = |x + 3| are absolute values, we ...”
June 15, 2018
GMATGuruNY posted a reply to A, B, C are three consecutive positive integers (A>B>C in the Problem Solving forum
“Let A=3, B=2 and C=1. 2A + B + 3C = (2*3) + 2 + (3*1) = 11. Now plug A=3 into the answers to see which yields the value in blue. Only E works: 6A-7 = (6*3) - 7 = 18 -7 = 11. The correct answer is E.”
June 15, 2018
GMATGuruNY posted a reply to Is x greater than 3.25? in the Data Sufficiency forum
“Statement 1: 3.2535 ≤ x < 3.2545. When any value in the range above is rounded to the nearest thousandth, the result is 3.254. Since every value in the range above is greater than 3.25, the answer to the question stem is YES. SUFFICIENT. Statement 2: 3.245 ≤ x < 3.255. When any ...”
June 15, 2018
GMATGuruNY posted a reply to If |x - 2| = |x + 3|, x could equal in the Problem Solving forum
“Alternate approach: |a-b| = the distance between a and b. |a+b| = |a-(-b)| = the distance between a and -b. |x - 2| = |x + 3| implies the following: The distance between x and 2 is equal to the distance between x and -3. In other words, x must be HALFWAY BETWEEN -3 AND 2. Halfway between two ...”
June 15, 2018
GMATGuruNY posted a reply to If |x - 2| = |x + 3|, x could equal in the Problem Solving forum
“Case 1: signs unchanged x-2 = x+3 -2 = 3 Since the resulting equation is invalid, Case 1 is not possible. Case 2: signs changed in ONE of the absolute values x-2 = -x-3 2x = -1 x = -1/2. The correct answer is B.”
June 15, 2018
GMATGuruNY posted a reply to Bob is training for a fitness competition. In order to in the Problem Solving forum
“For any set of consecutive integers: count = biggest - smallest + 1. average = (biggest + smallest)/2. sum = (count)(median). Since Bob starts with 25 pull-ups and drops 1 pull-up each round until his final set of 11 pull-ups, the pull-ups are composed of the consecutive integers between ...”
June 15, 2018
GMATGuruNY posted a reply to The price of car A increased by 20 percent over the same in the Data Sufficiency forum
“= Car A increased by 20% = 1.2A. Car B decreased by 20% = 0.8B. The reduced price of car B was what percent of the original price of car A? (reduced B)/(original A) = (0.8B)/A = 0.8(B/A). To answer the question stem, we need to know the value of B/A. Question stem, rephrased: What is the ...”
June 14, 2018
GMATGuruNY posted a reply to Is x = 1? in the Data Sufficiency forum
“Statement 1: Substituting 3⁰ = 1 into the given equation, we get: x = x¹. Case 1: x=0 In this case, the answer to the question stem is NO. Case 2: x=1 In this case, the answer to the question stem is YES. Since the answer is NO in Case 1 but YES in Case 2, INSUFFICIENT. Statement 2: ...”
June 14, 2018
GMATGuruNY posted a reply to x and y are integers such that 4x^2 – y^2 +4x + 4y – 3 = in the Problem Solving forum
“Let x=1. Substituting x=1 into 4x² – y² + 4x + 4y – 3 = 0, we get: 4(1²) – y² + (4*1) + 4y – 3 = 0 4 – y² + 4 + 4y – 3 = 0 – y² + 4y + 5 = 0 y² - 4y - 5 = 0 (y-5)(y+1) = 0 y=5 or y=-1. If y=-1, then A, C and E are not true. If y=5, then D is not true. The correct ...”
June 14, 2018
GMATGuruNY posted a reply to There are 68 children in the cafeteria of a school and in the Problem Solving forum
“One formula for 3 overlapping groups: T = Group 1 + Group 2 + Group 3 - (exactly 2 groups) - 2(all 3 groups) The big idea with overlapping group problems is to SUBTRACT THE OVERLAPS. When we add together everyone in the three groups: Those in exactly 2 of groups are counted twice, so ...”
June 14, 2018
GMATGuruNY posted a reply to GMATPREP:Whales in the Critical Reasoning forum
“The remaining answer choices, negated: B: Among whale fossils that date from later than about fifty million years ago, some are fossils of whale species that drank only fresh water. C: Fossils of whale species that drank fresh water will be found in close proximity to fossils of whale ...”
June 13, 2018
GMATGuruNY posted a reply to During a sale, a clothing store sold each shirt at a price in the Data Sufficiency forum
“Statement 1: Since the average price for the MIXTURE of shirts and sweaters (21) is closer to the sweater price (25) than to the shirt price (15), the store sold more sweaters than shirts. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: Let x = shirts and y = sweaters. ...”
June 13, 2018
GMATGuruNY posted a reply to If n is a positive integer, is 3^4+3^{n+4} divisible by 5? in the Data Sufficiency forum
“3⁴ + 3^(n+4) = 3⁴ + (3^n)(3⁴) = 3⁴(1 + 3^n) = 3⁴(3^n + 1). The expression in blue will be divisible by 5 only if (3^n + 1) is a multiple of 5. Question stem, rephrased: Is (3^n + 1) a multiple of 5? Statement 1: Case 1: n=2, with the result that 3^n + 1 = 3² + 1 = 10. In this ...”
June 13, 2018
GMATGuruNY posted a reply to N is the 36th prime number. N has remainder 1 when it is div in the Problem Solving forum
“The 36th prime number must be ODD. When an odd number is divided by 2, the remainder is 1. The correct answer is C. A remainder must be a nonnegative integer. If this problem were to appear on the GMAT, option A -- a negative integer -- would not be offered as an answer choice.”
June 13, 2018
GMATGuruNY posted a reply to GMAT Prep in the Sentence Correction forum
“The OAs above and E are not analogous. In the OAs above, the omitted verb is a form of to be: Heated oil prices are expected to be higher this year than were = simple past tense form of to be. In E, the omitted verb is NOT a form of to be: Demographers would have to know a great deal more ...”
June 13, 2018
GMATGuruNY posted a reply to When n is divided by 2, 3, 5, 7 and 9, the remainder is 1. W in the Problem Solving forum
“Since n must yield a remainder when divided by 2, n cannot be even. Eliminate A. To yield a remainder of 1 when divided by 9, n must be equal to ONE MORE THAN A MULTIPLE OF 9. Thus, the correct answer choice must be equal to (MULTIPLE OF 9) + 1: B) 211 = 210 + 1 --> Nope. C) 421 = 420 + 1 ...”
June 12, 2018
GMATGuruNY posted a reply to A new cell phone plan is offering pricing based on average in the Data Sufficiency forum
“The prompt should require that q>0, and the question stem should provide a crystal clear referent for this. Also -- if we assume that this refers to Brandon''s 2001 average monthly usage -- the question stem can be answered even without the two statements: Was Brandon''s 2001 average monthly ...”
June 12, 2018
GMATGuruNY posted a reply to tricky challenge question - Is CB || ED? in the Data Sufficiency forum
“Statements combined: Case 1: https://i1262.photobucket.com/albums/ii605/gmatguruny/triangles%20and%20parallelism_case%201_zps4waibbnr.png In this case, ∠B = ∠E and ∠C = ∠D, so CB || ED. Case 2: ...”
June 12, 2018
GMATGuruNY posted a reply to Overlapping sets in the Data Sufficiency forum
“An explanation for the formula below can be found in my post here: https://www.beatthegmat.com/og-13-178-virtual-reality-t111188.html Here is the formula with regard to the prompt above: Total = A + E + N - (AE + AN + EN) - 2(AEN) + None. The prompt gives values for A, E, N, AE, AN, and EN. ...”
June 12, 2018
GMATGuruNY posted a reply to Tricky question- Are x and y integers? in the Data Sufficiency forum
“The derived equation is valid in the following sense: If x and y are values such that their product is an integer and their sum is an integer -- as required by the two statements -- then we can conclude that x²+y² = integer. x=y=√2 is irrelevant because it violates the condition in red. The ...”
June 11, 2018
GMATGuruNY posted a reply to Crowan throws 3 dice and records the product of the numbers in the Problem Solving forum
“Case 1: all fives P(1st roll is 5) = 1/6. P(2nd roll is 5) = 1/6. P(3rd roll is 5) = 1/6. Since we want all of these events to happen together, we multiply the fractions: 1/6 * 1/6 * 1/6 = 1/216. Case 2: two 5''s and one roll that is 1 or 3 P(1st roll is 5) = 1/6. P(2nd roll is 5) = 1/6. ...”
June 11, 2018
GMATGuruNY posted a reply to A lawn care company has five employees, and there are ten in the Problem Solving forum
“The posted problem has been transcribed from the original source -- the book GMAT for Dummies -- incorrectly. In the book, the prompt reads as follows: Number of houses that could be assigned to the first employee = 10. (Any of the 10 houses.) Number of houses that could be assigned to the ...”
June 11, 2018
GMATGuruNY posted a reply to Beth has a collection of 8 boxes of clothing for a charity in the Problem Solving forum
“Let c=2, implying that the average number of pieces per box = 2. Total number of pieces = (number of boxes)(average per box) = 8*2 = 16. When a 12-piece box is removed, the resulting total = 16-12 = 4. When a 22-piece box is added, the resulting total = 4+22 = 26. Resulting average = (total ...”
June 11, 2018
GMATGuruNY posted a reply to Is z an integer? in the Data Sufficiency forum
“Statement 1: Options for 2z: 2z = 2, 4, 6, 8, 10, 12... Dividing every value above by 2, we get the following options for z: z = 1, 2, 3, 4, 5, 6... In every case, z is an integer. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: Options for 4z: 4z = 2, 4, 6, 8, 10, ...”
June 11, 2018
GMATGuruNY posted a reply to work in the Problem Solving forum
“Let the rate for each child = 1 unit per day. Since each child does half the work of a man, the rate for each man = 2 units per day. Since each woman does double the work of a man, the rate for each woman = 4 units per day. Combined rate for 3 men, 4 women and 6 children = (3*2) + (4*4) + (6*1) ...”
June 11, 2018
GMATGuruNY posted a reply to What is the value of y? in the Data Sufficiency forum
“Statement 1: 3|x² – 4| = y – 2. If x=0, then y=14. If x=2, then y=2. Since y can be different values, INSUFFICIENT. Statement 2: |3 – y| = 11. Solving 3-y = 11 and 3-y = -11, we get: y = -8 or y=14. Since both y = -8 and y=14 are possible, INSUFFICIENT. Statements 1 and 2 ...”
June 11, 2018
GMATGuruNY posted a reply to The sum of 3 consecutive numbers is definitely: in the Problem Solving forum
“Try to show that four of the five answer choices are WRONG. Case 1: -2, -1, 0 Sum = -2 + (-1) + 0 = -3. The resulting sum is not positive, nor is it divisible by 2, 4 or 5. Eliminate A, B, D and E. The correct answer is C. The sum of 3 consecutive integers can be represented and then ...”
June 11, 2018
GMATGuruNY posted a reply to Tricky question- Are x and y integers? in the Data Sufficiency forum
“In DS, each statement is a PREMISE: a fact that cannot be disputed. The premise in Statement 2 is that x+y = integer. Your conclusion -- that x²+y² = integer -- is based upon this premise.. √2 violates this premise and thus is not a valid case when the statements are combined.”
June 10, 2018
GMATGuruNY posted a reply to Tricky question- Are x and y integers? in the Data Sufficiency forum
“Both statements are satisfied by the following cases: Case 1: x=0 and y=0, with the result that xy=0 and x+y=0 In this case, x and y are both integers, so the answer to the question stem is YES. Case 2: x=√2 and y=-√2, with the result that xy=-2 and x+y=0 In this case, x and y and NOT ...”
June 10, 2018
GMATGuruNY posted a reply to In February 1995, Doris Schopper became president in the Sentence Correction forum
“the B: Doris Schopper became president of the international council of Medecins sans Frontieres, the English for “Doctors Without Borders" Here, the English seems to refer to the phrase in red, conveying that the phrase in red = ENGLISH. Not so. The phrase in red is composed of FRENCH ...”
June 9, 2018
GMATGuruNY posted a reply to Abby, Brandon, Cedric, and Deirdre are planning to attend a in the Problem Solving forum
“The total price for 4 people (A, B, C and D) is the same as the total price for 5 people (A, B, C, D and K). Let the total price = the LCM of 4 and 5 = $20. If A, B, C and D pay a total price of $20, the price per ticket = 20/4 = $5. If A, B, C, D and K pay a total price of $20, the price per ...”
June 8, 2018
GMATGuruNY posted a reply to James started from his home and drove eastwards at a in the Problem Solving forum
“Alternate approach: Let James'' rate = 3 mph. James started from his home and drove eastwards at a constant speed. Exactly 90 minutes after James stated from his home, his brother Patrick started from the same point and drove in the same direction as James did at a different constant speed. ...”
June 8, 2018
GMATGuruNY posted a reply to James started from his home and drove eastwards at a in the Problem Solving forum
“Let James'' rate = 3 mph. James started from his home and drove eastwards at a constant speed. Exactly 90 minutes after James stated from his home, his brother Patrick started from the same point and drove in the same direction as James did at a different constant speed. Patrick overtook James ...”
June 8, 2018
GMATGuruNY posted a reply to Sun and Moon: Difficult one in the Sentence Correction forum
“X and also Y is a valid construction. In this construction, also is used for emphasis: it serves to indicate that Y is somehow notable. An OA in GMATPrep: The organic food industry has organized a successful grassroots campaign -- using websites, public meetings, and also mass mailings. Here, ...”
June 8, 2018
GMATGuruNY posted a reply to Crowan throws 3 dice and records the product of the numbers in the Problem Solving forum
“A odd multiple of 25 will be yielded if the product is composed of two 5''s and an odd integer. Case 1: Crowan rolls three 5''s P(5 on the 1st roll) = 1/6. (Of the 6 possible rolls, one is 5.) P(5 on the 2nd roll) = 1/6. P(5 on the 3rd roll) = 1/6. Since we want all of these events to ...”
June 8, 2018
GMATGuruNY posted a reply to If xyz=x, is x=0? in the Data Sufficiency forum
“Statement 1: Substituting yz=0 into xyz = x, we get: x*0 = x 0 = x. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: Substituting xy=0 into xyz = x, we get: 0*z = x 0 = x. Thus, the answer to the question stem is YES. SUFFICIENT. The correct answer is D.”
June 8, 2018
GMATGuruNY posted a reply to An ant is clinging to one corner of a box in the shape of a in the Problem Solving forum
“https://s22.postimg.cc/60lk6c44d/Cubo.png Let the initial vertex = A, implying that the ant must travel to G. Let''s divide the journey into 3 stages and count the number of options for each stage. First stage; Since the ant can travel from A to B, D, or E, the number of options for the ...”
June 8, 2018
GMATGuruNY posted a reply to Speed/Distance in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the initial speed. When the correct answer is plugged in, increasing the speed by 10 kph will enable the cyclist to travel 25 km in 5 fewer minutes. Since the increase in the speed and the total distance are both multiples of 10, the correct answer is ...”
June 8, 2018
GMATGuruNY posted a reply to The ACME company manufactured x brooms per month from in the Problem Solving forum
“Let x=2, implying that 2 brooms are manufactured each month January through April.. Since January through April = 4 months, the number of brooms manufactured = 4*2 = 8. For the rest of the year, the number brooms sold each month = x/2 = 2/2 = 1. Implication: Starting in May, ACME''s stock of ...”
June 7, 2018
GMATGuruNY posted a reply to One gallon of soft drink is made of 40% orange juice and 60% in the Problem Solving forum
“If 40% juice and 100% juice are combined in EQUAL AMOUNTS, the resulting juice concentration will be the AVERAGE of the two percents: (40+100)/2 = 70. Thus, if 1 gallon of soft drink (which is 40% juice) is combined with 1 gallon of pure juice (which is 100% juice), the resulting mixture will be ...”
June 7, 2018
GMATGuruNY posted a reply to If 5 percent of the personnel stationed at army base M are o in the Data Sufficiency forum
“While you seem to have arrived at the correct answer, your approach might prove problematic for other problems. For example: Your first equation: (5/100)(M + F) = officers Here, F = the total number of females. For this reason, a stand-alone F should represent the total number of females in ...”
June 7, 2018
GMATGuruNY posted a reply to In the x-y plane, does the parabola y=ax^2+bx+c have x-inter in the Data Sufficiency forum
“For any parabola of the form y = ax² + bx + c, the DISCRIMINANT is equal to b² - 4ac. If the discriminant is positive, then the parabola has two x-intercepts. If the discriminant is equal to 0, then the parabola has one x-intercept. If the discriminant is negative, then the parabola has no ...”
June 7, 2018
GMATGuruNY posted a reply to How many integers between 50 and 100, inclusive, are divisi in the Problem Solving forum
“Total integers = (multiples of 2) + (multiples of 3) - (multiples of both 2 and 3). For any evenly spaced set: Count = (biggest - smallest)/increment + 1. The INCREMENT is the difference between one value and the next. Multiples of 2 between 50 and 100, inclusive: Smallest = 50. Biggest = ...”
June 7, 2018
GMATGuruNY posted a reply to Which of the following best completes the passage below in the Critical Reasoning forum
“Premise: 2/5 of the surveyed job applicants admitted to being dishonest (implying that 3/5 of the surveyed applicants claimed to be totally honest). Conclusion: The survey may underestimate the proportion of job applicants who are dishonest. A: Some dishonest people taking the survey might have ...”
June 6, 2018
GMATGuruNY posted a reply to Speed/Distance in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the distance traveled at 4 kph. Since all of the values in the problem are INTEGERS, the correct answer is almost certain to be a multiple of 4. Of the 5 options, only C is a multiple of 4. When the correct answer is plugged in, the total time = 9 ...”
June 6, 2018
GMATGuruNY posted a reply to At a certain organisation, the number of in the Problem Solving forum
“This is a MIXTURE problem. Percent change for men = +12%. Percent change for women = -6%. Percent change for the MIXTURE of men and women = +1.2%. The following approach is called ALLIGATION -- a very efficient way to handle MIXTURE PROBLEMS. Let M = men and W = women. Step 1: Plot the 3 ...”
June 6, 2018
GMATGuruNY posted a reply to Is a < 2? in the Data Sufficiency forum
“The answer to the question stem can be NO -- implying that a≥2 -- only if a is positive. Thus, when we evaluate the statements, we need consider only POSITIVE values for a. Statement 1: In the xy-plane, the point (a, 1) lies inside the circle whose equation is x^2 + y^2 = 3. Every point (x, ...”
June 6, 2018
GMATGuruNY posted a reply to How many of the positive divisors of 120 are also multiples in the Problem Solving forum
“120 = 4*30 = 4 * (2*3*5). To form a multiple of 4 that divides evenly into 120 but is not equal to 120, we must combine 4 with up to two of the factors in blue: 4 4*2 4*3 4*5 4*2*3 4*2*5 4*3*5 Total options = 7. The correct answer is D.”
June 6, 2018
GMATGuruNY posted a reply to A bakery sells white bread for certain price and rye in the Data Sufficiency forum
“What is the value of 2W + 3R? Statement 1: 2W + 2R = 880. No ways to determine the value of 2W + 3R. INSUFFICIENT. Statement 2: 4W + 6R = 2220 2R + 3W = 1110. SUFFICIENT. The correct answer is B.”
June 6, 2018
GMATGuruNY posted a reply to A rectangular tiled patio is composed of 70 square tiles. in the Problem Solving forum
“Let R = the number of rows and C = the number of columns. Total number of tiles = RC. Since there are 70 tiles, we get: 70 = RC. We can PLUG IN THE ANSWERS, which represent the value of R. The equation in blue indicates that the value of R must be a FACTOR OF 70. Of the five answer ...”
June 6, 2018
GMATGuruNY posted a reply to work in the Problem Solving forum
“Since 16 men working for 12 days are the equivalent of 24 children working for 18 days, we get: (16m)(12) = (24c)(18) 4m = 9c m = (9/4)c. Let the rate for each child = 4 units per day, implying that the rate for each man = (9/4)(4) = 9 units per day. Since 24 children complete the job in 18 ...”
June 5, 2018
GMATGuruNY posted a reply to Analysts blamed May’s sluggish retail in the Sentence Correction forum
“Generally, COMMA + VERBing serves to modify the nearest preceding action and the agent of that action. Analysts blamed May’s sluggish retail sales on unexciting merchandise as well as the weather, which was colder and wetter than usual in some regions, slowing sales of barbecue grills. Here, the ...”
June 5, 2018
GMATGuruNY posted a reply to Is xy<6? in the Data Sufficiency forum
“Statements combined: Case 1: x=0 and y=0 In this case, xy < 6. Case 2: x=-10 and y=-10 in this case, xy > 6. Since the answer is YES in Case 1 but NO in Case 2, the two statements combined are INSUFFICIENT. The correct answer is E.”
June 5, 2018
GMATGuruNY posted a reply to If a triangle has one side of 3 cm and another side in the Data Sufficiency forum
“Statement 1: Case 1: The triangle is 3-4-5 In this case, the third side -- the hypotenuse -- has a length of 5. Case 2: hypotenuse = 4 In this case, a² + 3² = 4⁴. Thus, the length of the third side -- the value of a --- will NOT be 5. Since the third side can have different lengths, ...”
June 5, 2018
GMATGuruNY posted a reply to If 2x = 3y = 10, then 12xy = ? in the Problem Solving forum
“Since 2x=10 and 3y=10, we get: (2x)(3y) = 10*10 6xy = 100 12xy = 200. The correct answer is B.”
June 5, 2018
GMATGuruNY posted a reply to Is xy<0? in the Data Sufficiency forum
“Question stem, rephrased: Do x and y have different signs? Statement 1: |x+y| < |x| + |y| Since an absolute value cannot be negative, both sides here are NONNEGATIVE, allowing us to SQUARE the inequality: (|x+y|)² < (|x| + |y|)² x² + y² + 2xy < x² + y² + 2|x||y| 2xy < ...”
June 5, 2018
GMATGuruNY posted a reply to work in the Problem Solving forum
“Let the job = 40 units. Since A takes 10 days to complete the job, A''s rate = w/t = 40/10 = 4 units per day. Since B takes 20 days to complete the job, B''s rate = w/t = 40/20 = 2 units per day. Since C takes 40 days to complete the job, C''s rate = w/t = 40/40 = 1 unit per day. Work completed ...”
June 5, 2018
GMATGuruNY posted a reply to progressions in the Problem Solving forum
“For any EVENLY SPACED SET: Count = (biggest - smallest)/(increment) + 1. Average = (biggest + smallest)/2. Sum = (count)(average). The INCREMENT is the difference between successive values. Even numbers between 10 and 300, inclusive: Here, the integers are EVEN, so the increment = 2. Count ...”
June 5, 2018
GMATGuruNY posted a reply to There are x teams and each team plays each other once in the Problem Solving forum
“Each game is played by a PAIR OF TEAMS. Since every team must play every other team exactly once, the total number of games is to equal to the number of possible pairs that can be formed from the x teams. We can PLUG IN THE ANSWERS, which represent the value of x. When the correct answer is ...”
June 4, 2018
GMATGuruNY posted a reply to When x and n are positive integers, if x^{2n}>(3x)^n, whi in the Problem Solving forum
“x^(2n) > (3x)^n (x^n)² > (3^n)(x^n) (x^n)(x^n) > (3^x)(x^n) x^n > 3^n. Since each side of the resulting inequality has the same exponent, the left side will be greater than the right side only if x > 3. The correct answer is A.”
June 4, 2018
GMATGuruNY posted a reply to 30^20 – 20^20 is divisible by all 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. 3²⁰ - 2²⁰ = (multiple of 3) - (non-multiple of 3) = non-multiple of 3. Since 3²⁰ - 2²⁰ is not divisible by 3, it cannot be divisible by a multiple of 3 such as 60. ...”
June 4, 2018
GMATGuruNY posted a reply to Abby and Bobby type at constant rates of 80 words per minute in the Problem Solving forum
“For Abby to CATCH-UP by 600 words and type AHEAD 200 words, she must type a total of 800 more words than Charlie. When people compete, SUBTRACT THEIR RATES. Since Bobby types 60 words per minute, and Abby types 80 words per minute, every minute Abby types 20 more words than Bobby -- the DIFFERENCE ...”
June 4, 2018
GMATGuruNY posted a reply to The nephew of Pliny the Elder wrote the only eyewitness in the Sentence Correction forum
“Correct! Correct!”
June 4, 2018
GMATGuruNY posted a reply to work in the Problem Solving forum
“Let the job = 15 units. Since A and B take 5 days to produce the 15-unit job, A+B = w/t = 15/5 = 3 units per day. Thus: A+B = 3. Since 2A and (1/3)B take 3 days to produce the 15-unit job, 2A + (1/3)B = w/t = 15/3 = 5 units per day. Thus: 2A + (1/3)B = 5 6A + B = 15. Subtracting the ...”
June 3, 2018
GMATGuruNY posted a reply to work in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent B''s time to produce the entire job alone. Since B takes 44 days to produce part of the job, B''s time to produce the entire job must be more than 44 days. Eliminate A and B. When the correct answer is plugged in, the time for B to complete the job ...”
June 3, 2018
GMATGuruNY posted a reply to work in the Problem Solving forum
“Let Q = 1 liter per turn. Since P has 3 times the capacity of Q, P = 3 liters per turn. Since P takes 60 3-liter turns to fill the drum, the drum = 60*3 = 180 liters. Since P = 3 liters per turn and Q = 1 liter per turn, the number of turns for P and Q together to fill the 180-liter drum = ...”
June 3, 2018
GMATGuruNY posted a reply to work in the Problem Solving forum
“Let the tank = 6 liters. Since one tap takes 6 hours to fill the 6-liter tank, the rate for each tap = w/t = 6/6 = 1 liter per hour. Time for one tap to fill half the 6-liter tank = w/r = 3/1 = 3 hours. After 3 additional taps are opened, the combined rate for 4 taps = 4 liters per hour. Time ...”
June 3, 2018
GMATGuruNY posted a reply to In numerous factories, automated equipment is in the Critical Reasoning forum
“Premise: In numerous factories, automated equipment is replacing employees. Conclusion: Factories that fire employees will eventually pay...through a heavier tax burden and unemployment insurance fees. C: Most employees that have been replaced by automated equipment are unskilled workers and ...”
June 3, 2018
GMATGuruNY posted a reply to Released the first Friday of every month and covering the in the Sentence Correction forum
“A and B: amount of new jobs Here, amount cannot serve to refer to a countable noun such as jobs. Eliminate A and B. D: the...report disclosed the number of new jobs that are created E: the...report disclosed the number of new jobs that have been created Here, it is not possible that the ...”
June 3, 2018
GMATGuruNY posted a reply to Last year the price per share of Stock X increased by k % in the Problem Solving forum
“Original ratio: Let the original price = 1 and the original earnings = 1. Resulting ratio: price/earnings = 1/1 = 1. New ratio: Let k=200 and m=100. Since the price increases by k=200%, the new price = 1 + (200/100)(100) = 3. Since the earnings increase by m=100%, the new earnings = ...”
June 3, 2018
GMATGuruNY posted a reply to In the sequence a_1, a_2, . . . , a_n each term in the Problem Solving forum
“For any evenly spaced set: average = median. sum = (count)(average). a₁ + a₁₁ + a₂₁ = 99. In the given sequence, the difference between one term and the next = c. Implication: {a₁, a₁₁, a₂₁} constitutes an evenly spaced set because the difference between one term and the ...”
June 3, 2018
GMATGuruNY posted a reply to Set X contains 10 consecutive integers. If the sum of the in the Problem Solving forum
“For any set of consecutive integers: average = median. sum = (count)(median). Since the sum of the 5 smallest integers = 265, we get: 265 = (5)(median) median = 265/5 = 53. Thus, the 5 smallest integers are 51, 52, 53, 54, and 55, implying that the 5 largest integers are 56, 57, 58, 59, ...”
June 2, 2018
GMATGuruNY posted a reply to The distance between West-Town to East-Town is 15 kilometers in the Problem Solving forum
“Since the two birds travel toward each other, they WORK TOGETHER to cover the 15 kilometers between them. When elements work together, ADD THEIR RATES. The combined rate for the two birds = 4+1 = 5 kpm. Of every 5 kilometers traveled by the two birds working together, 4 kilometers are traveled ...”
June 2, 2018
GMATGuruNY posted a reply to The flow of water through a drainage pipe was monitored for in the Problem Solving forum
“Let F = the first hour and T = the third hour. Since the second-hour rate is 50% faster than the first-hour rate, the second-hour rate (15 gallons) is 150% of the first-hour rate: 15 = (150/100)F 15 = (3/2)F 30 = 3F F = 10 gallons. Since 25% more water flows during the third hour than ...”
June 2, 2018
GMATGuruNY posted a reply to Today Jim is twice as old as Fred, and Sam is 2 years in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent Jim''s current age. When the correct answer is plugged in, Jim''s age four years ago will be 4 times Sam''s age four years ago. B: J=12 Since Jim is twice as old as Fred, F=6. Since Sam is 2 years younger than Fred, S=4. Four years ago, J = 12-4 = 8 ...”
June 1, 2018
GMATGuruNY posted a reply to A set X; {a1, a2, a3, a4, a5} with non-zero elements have in the Problem Solving forum
“Let Set X = {1, 2, 3, 4, 5} Since the set is evenly spaced, the average is equal to the median: M = 3. Since Set Y = {A₁-1, A₂-2, aA₃-3, A₄+5, A₅+1}, we get: Set Y = (0, 0, 0, 9, 6}. Mean of Set Y = (0+0+0+9+6)/5 = 3. As illustrated by the values in blue, the mean of Set Y = M. ...”
June 1, 2018
GMATGuruNY posted a reply to Is x an even integer? in the Data Sufficiency forum
“Statement 1 indicates that x is a perfect square: 1, 4, 9, 16, 25, 36, 49, 64... Statement 2 indicates that x is a perfect cube: 1, 8, 27, 64... When the statements are combined, x must be equal to a value contained in both lists. Thus: It''s possible that x=1. It''s possible that x=64. ...”
June 1, 2018
GMATGuruNY posted a reply to In the sequence {A_n}, A1=1 and An = 3An-1 + 1 for all posit in the Problem Solving forum
“A₁ = 1. A₂ = 3A₁ + 1 = (3*1) + 1 = 4. A₃ = 3A₂ + 1 = (3*4) + 1 = 13. A₄ = 3A₃ + 1 = (3*13) + 1 = 40. A₅ = 3A₄ + 1 = (3*40) + 1 = 121. A₆ = 3A₅ + 1 = (3*121) + 1 = 364. The results above indicate that the units digits repeat in a CYCLE OF 4: 1, 4, 3, 0...1, 4, 3, 0... ...”
June 1, 2018
GMATGuruNY posted a reply to The nephew of Pliny the Elder wrote the only eyewitness in the Sentence Correction forum
“The nearest eligible verb should be the main verb of the following clause. The blue statement above refers to answer choices that are incorrect because the nearest eligible verb is NOT the main verb of the following clause.”
June 1, 2018
GMATGuruNY posted a reply to ratios in the Problem Solving forum
“Container 1 : Container 2 : Container 3 = 3:4:5. In Container 1, M:W = 4:1, implying that water constitutes 1/5 of Container 1. In Container 2, M:W = 3:1, implying that water constitutes 1/4 of Container 2. In Container 3, M:W = 5:2, implying that water constitutes 2/7 of Container 3. The ...”
June 1, 2018
GMATGuruNY posted a reply to In a high school debating team consisting of 2 freshmen, in the Problem Solving forum
“Two of the four grades must be selected to represent the team at the championship. Because each grade on the debate team offers the same number of students -- 2 students per grade -- the probability of picking each grade is the same. Thus, the problem can be rephrased as follows: What is the ...”
May 31, 2018
GMATGuruNY posted a reply to J = x rounded to the nearest TENTH, and K = x rounded to the in the Problem Solving forum
“Since J = x rounded to the nearest tenth, J = 0.a (where a is a digit 0-9). Since K = x rounded to the nearest thousandth, K = 0.bcd (where b, c and d are any digits 0-9). The value of K implies that J-K can have at most three digits to the right of the decimal. Eliminate B, D and E. To ...”
May 31, 2018
GMATGuruNY posted a reply to profit and loss in the Problem Solving forum
“At a price of $10 each, 100 seats are sold. For every $2 increase in the price per seat, 5 fewer seats will be sold. The following options are implied: 12*95 = 12(100-5) = 1200-60 = 1140. 14*90 = 1260. 16*85 = 16(80+5) = 1280+80 = 1360. In the blue option, $1360 in revenue is yielded by a seat ...”
May 31, 2018
GMATGuruNY posted a reply to ratios in the Problem Solving forum
“Day crew: Let the number of workers = 5. Let the number of boxes loaded by each worker = 4. Total number of boxes loaded = 5*4 = 20. Night crew: Since the night crew has 4/5 as many workers as the day crew, the number of workers on the night crew = (4/5)5 = 4. Since each worker on the ...”
May 31, 2018
GMATGuruNY posted a reply to ratios in the Data Sufficiency forum
“Statement 1: Among the blue-eyed wolves, the ratio of grey coats to white coats is 4:3. Since (blue-eyed grey):(blue-eyed white) = 4:3 -- and 4+3 = 7 -- the total number of blue-eyed wolves must be a MULTIPLE OF 7. Since there are MORE THAN 3 blue-eyed white wolves, the least possible case is as ...”
May 31, 2018
GMATGuruNY posted a reply to In the sequence {An}, A1=1 and An=An-1+ …. +A1. What is th in the Problem Solving forum
“To avoid confusion, the GMAT would probably rephrase the prompt along the following lines: Each term after the first two terms is equal to the sum of the preceding terms: A₃ = 2 + 1 = 3. A₄ = 3 + 2 + 1 = 6. A₅ = 6 + 3 + 2 + 1 = 12. A₆ = 12 + 6 + 3 + 2 + 1 = 24. The results ...”
May 31, 2018
GMATGuruNY posted a reply to At a certain library, 12 students borrowed a total of in the Problem Solving forum
“Statement I: 9 students borrow 6 books each Let the other 3 students be A, B and C. Since 9 students borrow 6 books each, the list of borrowed books is as follows: A, B, C, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6. Books borrowed by A+B+C = (total books borrowed) - (books borrowed by the 9 students in blue) ...”
May 31, 2018
GMATGuruNY posted a reply to Jack gave 20% discount on sale of 15 toys & generated in the Problem Solving forum
“First day: $600 in revenue yields a profit of 25% = 1/4. Implication: The $600 in revenue is equal to 5/4 of the cost of 15 toys: 600 = (5/4)C C = 480. Thus: Profit for the 15 toys on the first day = (revenue) - (cost) = 600-480 = 120. Second day: The $600 first-day revenue includes a ...”
May 31, 2018
GMATGuruNY posted a reply to John spent 72% of his budget on fruits (including apples) in the Problem Solving forum
“Let John''s budget = $100. Since 72% of the budget is spent on fruit, the amount spent on fruit = $72. Since 54% of the budget is spent on apples, the amount spent on apples = $54. What percent of the money spent on fruit was not spent on apples? Of the $72 spent on fruit, the amount not spent ...”
May 31, 2018
GMATGuruNY posted a reply to The price of onions increases by 25%, by what percent should in the Problem Solving forum
“Let the original price per onion = $4, implying that the price per onion after a 25% increase = $4 + (25% of 4) = 4 + 1 = $5. Let the total amount spent in each case = the LCM of the two prices = $20. Number of onions purchased at the original $4 price = (total spent)/(price per onion) = 20/4 = ...”
May 30, 2018
GMATGuruNY posted a reply to In the initial planning stages, the condominium corporation in the Sentence Correction forum
“In B and C, their (plural) does not agree with corporation (singular). Eliminate B and C. D: only were taken...not those Here, were taken (verb) is illogically contrasted with those (pronoun). Eliminate D. E: only taken...not those Here, taken (participle) is illogically contrasted with ...”
May 30, 2018
GMATGuruNY posted a reply to In the last twenty years, despite the chauvinism of European in the Sentence Correction forum
“In A and B, the present tense verbs are respected and are becoming cannot serve to express an action performed IN THE LAST TWENTY YEARS. Eliminate A and B. In C, California wines (subject) lacks a verb. The result is an incomplete sentence. Eliminate C. E implies the following: California ...”
May 30, 2018
GMATGuruNY posted a reply to Challenge question: On the x-y coordinate plane, lines j and in the Data Sufficiency forum
“Statement 1: Substituting x=1 and y=-3 into the equations for lines j and k, we get: Line j: b(1) - a(-3) = 5 b + 3a = 5. Line k: 2b(1) - 3a(-3) = -5 2b + 9a = -5. The two equations in green can be solved for a and b. Thus, the value of a+b can be determined. SUFFICIENT. Statement 2: a ...”
May 30, 2018
GMATGuruNY posted a reply to If the distances between each pair of consecutive ticks are in the Problem Solving forum
“- Since the ticks are equally spaced, the difference between x and 2¹¹ is equal to the the difference between 2¹¹ and 2¹⁰: x - 2¹¹ = 2¹¹ - 2¹⁰ x = 2¹¹ + 2¹¹ - 2¹⁰ x = 2¹⁰(2 + 2 - 1) x = 2¹⁰(3). The correct answer is B.”
May 30, 2018
GMATGuruNY posted a reply to If 5 percent of the personnel stationed at army base M are o in the Data Sufficiency forum
“Statements combined: Case 1: Total number of personnel = 5,200 Case 2: Total number of personnel = 5,200,000 Clearly, the number of non-officers in Case 2 will be greater than the number of non-officers in Case 1. Since the number of non-officers can be different values, the two statements ...”
May 29, 2018
GMATGuruNY posted a reply to If each of the 4 circles above has radius 1, what in the Problem Solving forum
“https://s22.postimg.cc/aompuia8t/four_circles.png Area of the blue square above = s² = 2² = 4. Area of each circle = πr² = π(1²) = π. Each unshaded portion in the blue square constitutes 1/4 of a circle. Thus, the 4 unshaded portions combined constitute one full circle. Shaded portion ...”
May 29, 2018
GMATGuruNY posted a reply to How many 4-digit integers have the form abcd, where b is eve in the Problem Solving forum
“The sum in red is incorrect. Correct: 900+540+180 = 1620. Could you please correct the typo in your post?”
May 29, 2018
GMATGuruNY posted a reply to The Metropolitan Cooking Academy surveyed in the Critical Reasoning forum
“sus- means beneath. -pect means look. to suspect = to LOOK BENEATH something and render a BELIEF about it. John suspects that the race will be difficult. Conveyed meaning: Having "looked beneath" the race, John BELIEVES that it will be difficult. TO SUSPECT + THAT-CLAUSE implies ...”
May 29, 2018
GMATGuruNY posted a reply to The operation # is defined to be multiplication. Which of th in the Problem Solving forum
“Ⅰ. x#1=x If we replace # with multiplication, we get: x*1 = x x = x. Since the resulting equation is valid, Statement I must be true. Eliminate B and C, which do not include Statement I. Ⅲ. x#y=y#x If we replace # with multiplication, we get: x*y = y*x xy = yx. Since the ...”
May 29, 2018
GMATGuruNY posted a reply to p, q, x, and y are positive integers. If p^mq^n=72, what is in the Data Sufficiency forum
“I believe that the prompt has a typo and should read as follows: Both statements are satisfied by the following cases: Case 1: p=2, m=3, q=3 and n=2, with the result that m>n, mn=3*2=6, and (p^m)(q^n) = 2³3² = 72 In this case, p+q = 2+3 = 5. Case 2: p=1, m=6, q=72 and n=1, with the ...”
May 29, 2018
GMATGuruNY posted a reply to If a set consists of all positive digits less than or in the Problem Solving forum
“The MODE of a set is the number that appears the most often. Positive digits less than or equal to 3: 1, 2, 3. Squares of these digits: 1, 4, 9. Resulting set when the two lists above are combined: 1, 1, 2, 3, 4, 9. In the resulting set, the number that appears the most often is 1. The ...”
May 28, 2018
GMATGuruNY posted a reply to One robot builds a robot in 1 hour, another one builds a in the Problem Solving forum
“Let each robot = 2 units. Since a faster robot takes 1 hour to produce a 2-unit robot, the rate for a faster robot = w/t = 2/1 = 2 units per hour. Since a slower robot takes 1 hour to produce a 2-unit robot, the rate for a slower robot = w/t = 2/2 = 1 unit per hour. Each additional robot produced ...”
May 28, 2018
GMATGuruNY posted a reply to Are x and y both positive? in the Data Sufficiency forum
“Statement 1: 2x-2y = 1. 2(x-y) = 1. x-y = 1/2. x = y + 1/2. It''s possible that y=1/2 and x=1. It''s possible that y=0 and x=1/2. Since in the first case x and y are both positive and in the second case x and y are not both positive, insufficient. Statement 2: x/y > 1. It''s possible ...”
May 28, 2018
GMATGuruNY posted a reply to A soda machine sells both bottles and cans, and no other in the Problem Solving forum
“Price per bottle = 150 cents. Price per can = 75 cents. Average price for the MIXTURE of bottles and cans = (total revenue)/(total number of beverages) = (315 dollars)/(250 beverages) = 63/50 dollars = 126/100 dollars = 126 cents. To determine the ratio of bottles to cans, we can use ...”
May 28, 2018
May 28, 2018
GMATGuruNY posted a reply to South Korea has witnessed the world's most dramatic growth in the Sentence Correction forum
“A: from conversions rather than the population Here, CONVERSIONS are illogically compared to THE POPULATION. Eliminate A. C: conversions instead of the...increasing Here, CONVERSIONS are illogically compared to THE INCREASING. D and E: Church membership is expanding by 6.6 percent a year, ...”
May 26, 2018
GMATGuruNY posted a reply to A lecture course consists of 595 students. The students are in the Problem Solving forum
“Number of discussion sections = (total number of students)/(number of students per section). section. Since the total number of students = 595, the number of students per section must be a FACTOR OF 595. The question stem asks for a value that CANNOT be the number of students per classroom. ...”
May 26, 2018
GMATGuruNY posted a reply to There are 8 disks in a container that are numbered 23, 24, in the Problem Solving forum
“P = (good outcomes)/(all possible outcomes). All possible outcomes: From the 8 numbers, the number of ways to choose 4 = 8C4 = (8*7*6*5)/(4*3*2*1) = 70. Good outcomes: For 27 to be the median of the 5 numbers, two of the 4 numbers selected must be LESS THAN 27, while the other two must be ...”
May 26, 2018
GMATGuruNY posted a reply to Mrs. Jones divided $120 evenly among her children. Tom, the in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the total number of children. When the correct answer is plugged in, Tom''s resulting amount = $12. B: 5 children, implying that the original share per child = 120/5 = 24 After Tom gives $6 to each of his 4 siblings, Tom''s resulting amount = 24 - ...”
May 25, 2018
GMATGuruNY posted a reply to Which of the following leads to the correct mathematical in the Problem Solving forum
“This problem does indeed require that we count the number of possible arrangements. BANANA = 6 letters. The number of ways to arrange 6 distinct elements = 6!. But the elements here are not all distinct. There are 3 identical A''s and 2 identical N''s. When an arrangement includes ...”
May 25, 2018
GMATGuruNY posted a reply to What is the remainder when 7^100 is divided by 50? in the Problem Solving forum
“If the last two digits of an integer form a value less than 50, then dividing the integer by 50 will yield a remainder equal to the last 2 digits of the integer: 121/50 = 2 R21 9044/50 = 180 R44 25038/50 = 500 R38. Examine the last two digits for small powers of 7 and look for a PATTERN: 7¹ ...”
May 25, 2018
GMATGuruNY posted a reply to To understand why some people are incapable to learn in the Sentence Correction forum
“A and B: some people are incapable to learn The portion in red is unidiomatic. Incorrect: X is incapable to do Y Correct: X is incapable OF doing Y Eliminate A and B. C: To understand...the brains of 96 convicts Here, to understand seems to refer to the brains, implying that THE BRAINS are ...”
May 25, 2018
GMATGuruNY posted a reply to The alarm of a certain clock rings every 15 minutes. If the in the Problem Solving forum
“After the first ring at 12:15, 23 additional rings are required to yield a total of 24 rings. Since the clock rings every 1/4 hour, and 23 additional rings are required, the total time needed for 23 additional rings = (¼)(23) = 5 ¾ hours = 5 hours, 45 minutes. Thus: 24th ring = (12:15) + (5:45) ...”
May 25, 2018
GMATGuruNY posted a reply to Let abcd be a general four-digit number and all the in the Problem Solving forum
“Step 1: Choose 3 digits Since 0 < d ≤ 9, a, b and c must be composed of 3 digits with a nonzero sum less than or equal to 9: 1, 2, 3 --> d = 1+2+3 = 6 1, 2, 4 --> d = 1+2+4 = 7 1, 2, 5 --> d = 1+2+5 = 8 1, 2, 6 --> d = 1+2+6 = 9 1, 3, 4 --> d = 1+3+4 = 8 1, 3, 5 --> d ...”
May 25, 2018
GMATGuruNY posted a reply to Three men and 2 women will present 5 consecutive speeches in the Problem Solving forum
“P(at least 2 men speak consecutively) = 1 - P(no men speak consecutively). For no men to speak consecutively, the order of the speeches must be as follows: man-woman-man-woman-man. P(1st speaker is a man) = 3/5. (Of the 5 speakers, 3 are men.) P(2nd speaker is a woman) = 2/4. (Of the 4 ...”
May 24, 2018
GMATGuruNY posted a reply to By approximately what percent did the sale of nonfiction in the Problem Solving forum
“According to the undashed line on the chart: Nonfiction in 1984 = 40%. Nonfiction in 1987 ≈ 58%. Thus: Percent increase from 40 to 58 = (difference/original) * 100 = (18/40) * 100 = 45%. The correct answer is A.”
May 24, 2018
GMATGuruNY posted a reply to It has been estimated that the annual cost to the United in the Sentence Correction forum
“In A, B and D, annual and a year are redundant. Eliminate A, B and D. E: It has been estimated...because of illiteracy. Here, a reader could construe that illiteracy CAUSES 20 billion a year to be estimated. Not the intended meaning. Eliminate E. The correct answer is C.”
May 24, 2018
GMATGuruNY posted a reply to The median of 5 numbers is 50, and their range is 40. If the in the Problem Solving forum
“I suspect that the question stem has a typo and should read as follows: The median of 5 numbers is 50. The median of the 3 smallest numbers is 40. The 5 numbers are as follows: __ 40 __ 50 __ __ Test whether I, II and III could be the range of the 3 largest numbers. If the ...”
May 24, 2018
GMATGuruNY posted a reply to How many 4-digit integers have the form abcd, where b is eve in the Problem Solving forum
“Case 1: b=0, implying that d ≥ 0 Number of options for d = 10. (Any of the 10 digits.) Number of options for a = 9. (Any digit 1-9.) Number of options for c = 10. (Any of the 10 digits.) To combine the options above, we multiply: 10*9*10 = 900. Case 2: b=2, implying that d ≥ 4 Number of ...”
May 24, 2018
GMATGuruNY posted a reply to When the digits of two-digit, positive integer M are reverse in the Data Sufficiency forum
“Let T = the TENS digit of M and U = the nonzero UNITS digit of M. Then: M = 10T + U. Since the digits in N are reversed, N = 10U + T. Resulting difference: M-N = (10T + U) - (10U + T) = 9T - 9U = 9(T-U). Since the greatest possible value of T-U = 9-1 = 8, M-N must be a MULTIPLE OF 9 NO ...”
May 24, 2018
GMATGuruNY posted a reply to If a and b are positive integers in the Data Sufficiency forum
“It is a good idea to know the following: 1/11 = 0.090909... Thus: 9/11 = 9(0.090909...) = 0.818181...”
May 23, 2018
GMATGuruNY posted a reply to At 8am on Thursday, two workers, A and B, each start working in the Problem Solving forum
“Worker A takes two 8-hour days to produce a lamp, for a total of 16 hours. Since Worker B finishes sometime Friday morning, B takes between 8 and 12 hours to produce a lamp. Let each lamp = 48 units. A''s rate = w/t = 48/16 = 3 unit per hour. If B takes 8 hours to produce a lamp, B''s rate = ...”
May 23, 2018
GMATGuruNY posted a reply to Is k^2 odd? in the Data Sufficiency forum
“The median for an EVEN NUMBER of consecutive integers will always be a NON-INTEGER: 1, 2 --> median = 1.5 1, 2, 3, 4 --> median = 2.5. 1, 2, 3, 4, 5, 6 --> median = 3.5. The median for an ODD NUMBER of consecutive integers will always be an INTEGER: 1, 2, 3 --> median = 2. 1, 2, ...”
May 23, 2018
GMATGuruNY posted a reply to Is x - y > 0? in the Data Sufficiency forum
“Question stem, rephrased: Is x > y? Statement 1: Case 1: y=0, implying that x > |0| and thus x > 0 Case 2: y=1, implying that x > |1| and thus x > 1 Case 3: y=-1, implying that x > |-1| and thus x > 1 Case 4: y=10, implying that x > |10| and thus x > 10 Case 5: ...”
May 23, 2018
GMATGuruNY posted a reply to If x and y are positive integers, does x/y = 7/9? in the Data Sufficiency forum
“Statement 1: Test whether it''s possible that x/y = 7/9 when x=103: 103/y = 7/9 7y = 103*9 y = (103*9)/7 = noninteger. Since y must be a positive integer, it is not possible that x/y = 7/9. Thus, the answer to the question stem is NO. SUFFICIENT. To compare fractions: 1. Multiply the ...”
May 23, 2018
GMATGuruNY posted a reply to In 2003, the number of girls attending Jefferson High in the Problem Solving forum
“Test the SMALLEST POSSIBLE CASE. Since both populations increase by 20% = 1/5, the original number of boys and the original number of girls must each be a multiple of 5. Since in 2003 there must be an equal number of boys and girls, the smallest possible case is as follows: 2003: boys = 5 and ...”
May 23, 2018
GMATGuruNY posted a reply to Much like the belief that the world is flat, challenged by in the Sentence Correction forum
“OA: Much like the belief that the world is flat, challenged by Galileo, there are currently widely-held hypotheses. Here, COMMA + challenged is incorrectly preceded by the clause in red. A COMMA + VERBed modifier must be preceded by a NOUN or NOUN PHRASE. Also, the referent for an introductory ...”
May 23, 2018
GMATGuruNY posted a reply to Low temperature in the Sentence Correction forum
“The conclusion in red is not necessarily true. and may serve to connect concurrent actions. Mary was sitting and reading. Here, the two actions in blue are performed at the same time.”
May 23, 2018
GMATGuruNY posted a reply to How many 4-digit integers have the form abcd, where b is eve in the Problem Solving forum
“Careful! The cases above are invalid because they violate the condition that b must be even.”
May 23, 2018
GMATGuruNY posted a reply to "A" and "B" run around a circular track in the Problem Solving forum
“Middle of the 5th round = 4.5 laps. (4 full laps + half of the 5th lap.) Since A''s rate = 70 seconds per lap, the time for A to complete 4.5 laps = (total number of laps)(number of seconds per lap) = (4.5)(70) = 315 seconds. We can PLUG IN THE ANSWERS, which represent the number of seconds for ...”
May 22, 2018
GMATGuruNY posted a reply to NUMBERS in the Problem Solving forum
“For the 3 words to be switched on simultaneously, each must reach the END OF ITS RESPECTIVE ON-OFF CYCLE. On-off cycle for RON: (3 seconds on) + (47/6 seconds off) = 18/6 + 47/6 = 65/6 seconds. On-off cycle for AND: (3 seconds on) + (4/3 seconds off) = 18/6 + 8/6 = 26/6 seconds. On-off cycle ...”
May 22, 2018
GMATGuruNY posted a reply to NUMBERS in the Problem Solving forum
“When an integer is raised to consecutive powers, the resulting units digits repeat in a CYCLE. 57867¹⁹²⁵⁷⁶: 7¹ --> units digit of 7. 7² --> units digit of 9. (Since the product of the preceding units digit and 7 = 7*7 = 49.) 7³ --> units digit of 3. (Since the product ...”
May 22, 2018
GMATGuruNY posted a reply to NUMBERS in the Problem Solving forum
“Make a list of two-digit numbers that are 18 less than a perfect square: 36-18 = 18 49-18 = 31 64-18 = 46 81-18 = 63 100-18 = 82 Check whether each option above is equal to 18 less than the square of its digit sum: 18 = (1+8)² - 18 31 = (3+1)² - 18 46 = (4+6)² - 18 63 = (6+3)² - 18 ...”
May 22, 2018
GMATGuruNY posted a reply to NUMBERS in the Problem Solving forum
“To MINIMIZE the number of rooms, we must MAXIMIZE the number of students per room. Let x = the number of students per room. Since each room must have x students -- and we want x to be as large as possible -- x must be equal to the GREATEST COMMON FACTOR of 315, 420, and 1155: 315 = 3*3*5*7 420 ...”
May 22, 2018
GMATGuruNY posted a reply to How many gallons of water must be mixed with 1 gallon in the Problem Solving forum
“Salt percentage in the original solution: 15%. Salt percentage in the added water: 0%. Salt percentage in the mixture: 10%. Let S = the original solution and W = the added water. The following approach is called ALLIGATION -- a very efficient way to handle MIXTURE PROBLEMS. Step 1: Plot ...”
May 22, 2018
GMATGuruNY posted a reply to How many gallons of water must be mixed with 1 gallon in the Problem Solving forum
“Amount of salt = 15% of 1 gallon = 0.15 gallon. We can PLUG IN THE ANSWERS, which represent the amount of water that must be added to reduce the salt concentration to 10%. B: 2/3 gallon Salt concentration = (amount of salt)/(new total volume) = 0.15/(1 + 2/3) = 0.15/(5/3) = (0.15 * 3)/5 = ...”
May 22, 2018
GMATGuruNY posted a reply to Publishers of travel guides for families typically suffer in the Sentence Correction forum
“B: vacations budgets are low and their efforts to save are intense Here, their seems to refer to vacation budgets -- the nearest preceding plural noun -- implying that the efforts of VACATION BUDGETS are intense. This meaning is nonsensical. Eliminate B. C: more intense efforts Here, it is ...”
May 22, 2018
GMATGuruNY posted a reply to x+y=? in the Data Sufficiency forum
“Statement 1: Case 1: x=0, with the result that y = 3x = 3*0 = 0 In this case, x+y = 0+0 = 0. Case 2: x=1, with the result that y = 3x = 3*1 = 3 In this case, x+y = 1+3 = 4. Since x+y can be different values, INSUFFICIENT. Statement 2: Neither side of the equation can be negative, since the ...”
May 22, 2018
GMATGuruNY posted a reply to If ABCD is square and both AED and CDF are equilateral in the Problem Solving forum
“Because triangles ADE and CDF are equilateral, we get: https://s9.postimg.cc/xtqgckd9n/square_and_equilateral_triangles_1.png Because triangle AED is equilateral, DE = AD. Because ABCD is a square, AD = CD. .Thus, DE=CD, with the result that triangle CDE is isosceles: ...”
May 22, 2018
GMATGuruNY posted a reply to A jar contains 6 red marbles and 9 blue marbles. If Evelyn in the Problem Solving forum
“Case 1: 2 green marbles P(1st marble is green) = 6/15. (Of the 15 marbles, 6 are green.) P(2nd marble is green) = 5/14. (Of the 14 remaining marbles, 5 are green.) To combine these probabilities, we multiply: 6/15 * 5/14 = 1/7. Case 2: 2 red marbles P(1st marble is red) = 9/15. (Of the 15 ...”
May 21, 2018
GMATGuruNY posted a reply to Money invested at x%, compounded annually, triples in value in the Problem Solving forum
“The posted problem has a typo and should read as follows: Since x=8, the approximate number of years for the investment to triple = 112/x = 112/8 = 14. Since the initial investment = 2500, and the amount triples about every 14 years, we get: After the first 14 years --> 3*2500 = 7500. ...”
May 21, 2018
GMATGuruNY posted a reply to In what year was Edward born? in the Data Sufficiency forum
“Test EXTREMES. Case 1: Lisa''s birth month = January 1970 Since Edward was born 14 months earlier, Edward''s birth month = November 1968. Case 2: Lisa''s birth month = December 1970 Since Edward was born 14 months earlier, Edward''s birth month = October 1969. Since Edward''s birth year ...”
May 21, 2018
GMATGuruNY posted a reply to On Monday, Karen had S dollars in her savings account in the Problem Solving forum
“Alternate approach: Let S=30. The answer choices imply the following options for C: A) C=-10 B) C=10 C) C=20 D) C= 90 E) C = 100 From here, we can PLUG IN THE ANSWERS. When the correct answer is plugged in, the two accounts will hold the same amount after the transfer on Wednesday. ...”
May 21, 2018
GMATGuruNY posted a reply to Machine A produces pencils at a constant rate of 9000 in the Problem Solving forum
“To minimize B''s time, we must maximize A''s time. Since each machine can work for at most 8 hours, let A''s time = 8 hours. Since A''s rate = 9000 pencils per hour, the number of pencils produced by A in 8 hours = rt = 9000*8 = 72,000. Remaining pencils = 100,000 - 72,000, = 28,000. Since B''s ...”
May 21, 2018
GMATGuruNY posted a reply to Last year's receipts from the sale of candy on Valentine's in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the total sales. Since 385 represents 7% of the total sales, 10% of the correct answer must be a little more than 385. Only D is viable: 10% of 5500 = 550. The correct answer is D.”
May 21, 2018
GMATGuruNY posted a reply to OG 10th Edition Q 74 in the Critical Reasoning forum
“The correct answer must support the conclusion that a well-balanced breakfast is a better vitamin source than is a fortified breakfast cereal.. A: In many foods, the natural combination of vitamins with other nutrients makes those vitamins more usable by the body than are vitamins added in ...”
May 21, 2018
GMATGuruNY posted a reply to A study done on children under the age of twelve showed in the Sentence Correction forum
“The intention here is to convey the following: The study showed THAT X IS TRUE but THAT Y IS TRUE. For the intended meaning to be conveyed clearly, the second that is required. A and B: The study...showed that....but for C: The study showed that...but when These options do not include the ...”
May 21, 2018
GMATGuruNY posted a reply to If 123,456=123a+87 and 234,567=123b+6, how many multiples o in the Problem Solving forum
“For any EVENLY SPACED SET: Count = (biggest - smallest)/increment + 1. The INCREMENT is the difference between successive terms. Smallest multiple of 123 between 123a + 87 and 123b + 6: 123a +123. Biggest multiple of 123 between 123a + 87 and 123b + 6: 123b. Since 123 is the increment ...”
May 21, 2018
GMATGuruNY posted a reply to Jayden draws a regular n-gon. What is the value of n? in the Data Sufficiency forum
“Sum of the interior angles of a quadrilateral = 360, with the result that each angle of a square = 360/4 = 90. For each additional side, the sum of the interior angles increases by 180: Sum of the interior angles of a pentagon = 360+180 = 540, with the result that each angle of a regular pentagon ...”
May 21, 2018
GMATGuruNY posted a reply to statements must be true for all integers a, b and c? in the Problem Solving forum
“a@b = a + b - ab. In other words, a@b = SUM - PRODUCT. Statement I is included in four of the five answer choices. Thus, it is almost certain that statement I must be true. Otherwise, a test-taker will be able to eliminate four answer choices simply by evaluating statement I. To save time, ...”
May 20, 2018
GMATGuruNY posted a reply to A boyis buying two kinds of marbles. One kind costs 25 cents in the Problem Solving forum
“I believe that the following represents the intent of the problem: Cost of 5 pounds of 25-cent marbles = 5*25 = 125 cents. We can PLUG IN THE ANSWERS, which represent the number pounds of 32-cent marbles. When the correct answer is plugged in the average cost per marble ≈ 29. B: 6 ...”
May 19, 2018
GMATGuruNY posted a reply to Two liquids are mixed in the ratio 3:2 and the vendor gains in the Problem Solving forum
“Since the selling price of $11 per liter represents a profit of 10%, the cost per liter = $10. The cost of the first liquid is $2 more than the cost of the second liquid. For the average cost per liter to be $10, the cost of the first liquid must be MORE THAN $10, while the cost of the second ...”
May 19, 2018
GMATGuruNY posted a reply to A farmer who grows strawberries defines . . . in the Data Sufficiency forum
“Statement 1: Since the size of the crop is unknown, we cannot determine how many workers must be hired for the crop to be picked in 15 days. INSUFFICIENT. Statement 2: For 13,500 liters to be picked in 15 days, the amount that must be picked each day = 13,500/15 = 900 liters. Since the rate ...”
May 19, 2018
GMATGuruNY posted a reply to Employment costs rose - GMATPrep in the Sentence Correction forum
“In B, it (singular) does not agree with costs (plural). Eliminate B. C: Employment costs rose...less than they were Here, an ACTION (rose) is illogically compared to a STATE-OF-BEING (were). Eliminate C. lower is an ADJECTIVE. It must serve to modify a NOUN. D and E: Employment costs ...”
May 19, 2018
GMATGuruNY posted a reply to OG 16 Question 27 in the Sentence Correction forum
“One reason to eliminate B: Generally, a COMMA + VERBing modifier must serve to express an action that is concurrent with the nearest preceding action. B implies the following: The Etruscan alphabet in turn had been adapted, adapting itself earlier. Here, the COMMA + VERBing action in red is ...”
May 18, 2018
GMATGuruNY posted a reply to Each of 60 mineral water bottles in a certain shipment is in the Problem Solving forum
“The addition of the word in red clarifies the intent of the problem: Curren total volume = (number of bottles)(average volume per bottle) = 60*800 = 48,000 ml. We can PLUG IN THE ANSWERS, which represent the number of 1000-ml bottles that must be removed to reduce the average volume per ...”
May 18, 2018
GMATGuruNY posted a reply to On May 1 of last year, Jasmin invested x dollars . . . . in the Data Sufficiency forum
“Statement 1: Since we know the interest rate (6% per year, compounded monthly) and the amount of interest earned after one month ($200), we can calculate the amount Jasmin must have invested. SUFFICIENT. Statement 2: Since we know the interest rate (6% per year, compounded monthly) and the ...”
May 18, 2018
GMATGuruNY posted a reply to The Number of students learning Three subjects are as in the Problem Solving forum
“https://s9.postimg.cc/nom8j2aej/math_english_science.png The values in blue represent the number of students studying exactly 1 subject. Sum of the values in blue: 125 - 2(a+b+c). To MINIMIZE the value of this expression, we must MAXIMIZE the value of a+b+c. Since the expression must be ...”
May 18, 2018
GMATGuruNY posted a reply to A shop sells two variants of chocolates - one that costs 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, Since the price of each chocolate is either $3 or $5, and the total amount sold = $108, we get: 3x + 5y = 108. Since 108 is an integer whose digits sum to a multiple of 3, 108 is a ...”
May 18, 2018
GMATGuruNY posted a reply to The number of coins that Lana and Brad had were in the in the Problem Solving forum
“An alternate approach is to PLUG IN THE ANSWERS, which represent the difference between Lana and Brad after the 8-coin gift. When the correct answer is plugged in, the ratio for Lana and Brad before the 8-coin gift = 5/2. D: 14 After the 8-coin exchange: The parts of the resulting ratio for ...”
May 17, 2018
GMATGuruNY posted a reply to Right now, a barrel of water is exactly 40% full of water. in the Data Sufficiency forum
“Since every value in the problem is either a fraction or a percentage -- and no actual volumes are given -- the capacity of the barrel can be any value. Thus, the two statements combines are INSUFFICIENT. The correct answer is E. The phrase in red is ambiguous and would not appear in an ...”
May 17, 2018
GMATGuruNY posted a reply to Is n an integer? in the Data Sufficiency forum
“Both statements are satisfied by the following cases: Case 1: n = 1, with the result that 2n = 2 and 1/n = 1 In this case, n is an integer, so the answer to the question stem is YES. Case 2: n = 1/2, with the result that 2n = 1 and 1/n = 2 In this case, n is NOT an integer, so the answer to the ...”
May 17, 2018
GMATGuruNY posted a reply to How many 4-digit numbers have only even digits? in the Problem Solving forum
“Number of options for the thousands digit = 4. (2, 4, 6, or 8) Number of options for the hundreds digit = 5. (0, 2, 4, 6, or 8) Number of options for the tens digit = 5. (0, 2, 4, 6, or 8) Number of options for the units digit = 5. (0, 2, 4, 6, or 8) To combine these options, we multiply: ...”
May 17, 2018
GMATGuruNY posted a reply to If xy < 4, is x < 2? in the Data Sufficiency forum
“Statement 1: Case 1: y=2 and x=1, with the result that xy < 4 In this case, x<2, so the answer to the question stem is YES. Case 2: y=3/2 and x=2, with the result that xy < 4 In this case, x=2, so the answer to the question stem is NO. Since the answer is YES in Case 1 but NO in Case ...”
May 16, 2018
GMATGuruNY posted a reply to What is the product of all the possible values of x if in the Problem Solving forum
“x²(x+2) + 7x(x+2) + 6(x+2) = 0. Factor out x+2: (x+2)(x² + 7x + 6) = 0 Factor the quadratic in red: (x+2)(x+6)(x+1) = 0 Option for x: x=-2, x=-6, x==-1. Thus, the product of all the solutions = (-2)(-6)(-1) = -12. The correct answer is B.”
May 16, 2018
GMATGuruNY posted a reply to There are 8 books in a shelf that consists of 2 paperback in the Problem Solving forum
“Combinations with at least 1 paperback = (all possible combinations) - (combinations with no paperbacks). All possible combinations: From the 8 books, the number of ways to choose 4 = 8C4 = (8*7*6*5)/(4*3*2*1) = 70. Combinations with no paperbacks: From the 6 hardback books, the number ...”
May 15, 2018
GMATGuruNY posted a reply to Although the bite of brown recluse spiders are rarely fatal in the Sentence Correction forum
“A and B: Although the bite...are rarely fatal Here, are (plural) does not agree with the bite (singular). Eliminate A and B. C: the bite...posing the greatest danger to the infant and elderly, who are particularly vulnerable to their poison Here, their (plural) does not agree with the bite ...”
May 15, 2018
GMATGuruNY posted a reply to In a certain theater, the first row has 12 seats, and each r in the Problem Solving forum
“Since each row has 1 more seat than the preceding row, the row tallies form a set of consecutive integers: 12, 13, 14...48, 49. 50. For any set of consecutive integers: Count = biggest - smallest + 1 Average = (biggest + smallest)/2 Sum = (count)(average). In the problem at hand: Smallest ...”
May 15, 2018
GMATGuruNY posted a reply to How many solutions are possible for the inequality | x - 1 | in the Problem Solving forum
“|a-b| = the DISTANCE between a and b. Thus: |x-1| = the distance between x and 1. |x-6| = the distance between x and 6. Question stem rephrased: For how many values of x is the sum of the two distances less than 2? The distance between 1 and 6 is 5. Thus, if x is BETWEEN the ...”
May 15, 2018
GMATGuruNY posted a reply to Trains A and B travel at the same constant rate in opposite in the Data Sufficiency forum
“Statement 1: Whereas A travels for 2 hours, B begins its journey 1 hour later and travels for 1 hour. A ----------2 hours----------> meeting spot <-----1 hour----- B Since A travels at r miles per hour for 2 hours to meet B, and B travels at r miles per hour for 1 hour to meet A, it takes a ...”
May 14, 2018
GMATGuruNY posted a reply to If x is a positive integer, what is the least common in the Data Sufficiency forum
“Statement 1: x must be a factor of 30 such that the smallest value divisible by both x and 6 is 30. Options for x: x=5, 10, 15, 30. In every case, the LCM for x , 6, and 9 is 90. SUFFICIENT. Statement 2: x must be a factor of 45 such that the smallest value divisible by both x and 9 is 45. ...”
May 14, 2018
GMATGuruNY posted a reply to If y is positive, what is the value of x? in the Data Sufficiency forum
“Since y is positive, |y| = y. Statement 1: x - y = -x - |y| x - y = -x - y x = -x 2x = 0 x = 0. SUFFICIENT. Statement 2: x = y-3 If y=1, then x = 1-3 = -2. If y=2, then x = 2-3 = -1. Since x can be different values, INSUFFICIENT. The correct answer is A.”
May 14, 2018
GMATGuruNY posted a reply to If a = 4b, what percent of 2a is 2b? in the Problem Solving forum
“= Let b=1, implying that a = 4b = 4*1 = 4. What percent of 2a is 2b? 2b/2a = b/a = 1/4 = 25%. The correct answer is C.”
May 14, 2018
GMATGuruNY posted a reply to John bought a shirt, a pair of pants, and a pair of shoes in the Problem Solving forum
“(pant cost)/(total cost) = 20/(10+20+30) = 20/60 = 1/3 = 33⅓%. The correct answer is D.”
May 14, 2018
GMATGuruNY posted a reply to Is |a| + |b| > |a + b| ? in the Data Sufficiency forum
“Is |a| + |b| > |a + b|? Because an absolute value cannot be negative, both sides of the inequality above are NONNEGATIVE, allowing us to SQUARE the inequality (|a| + |b|)² > (|a + b|)² a² + 2|a||b| + b² > a² + 2ab + b² 2|a||b| > 2ab |a||b| > ab. The resulting inequality ...”
May 14, 2018
GMATGuruNY posted a reply to Verbal Review 18 : Kudzu, an Asian vine in the Sentence Correction forum
“Generally, the usage of a passive verb implies one or both of the following: 1. The agent of the passive action is unknown. 2. The agent of the passive action is unimportant to the meaning of the sentence. The SC above is concerned primarily with the rampant GROWTH of Kudzu. To understand this ...”
May 13, 2018
GMATGuruNY posted a reply to Verbal Review 18 : Kudzu, an Asian vine in the Sentence Correction forum
“New genetic evidence provides compelling support for classifying Africa’s forest elephants and its savanna elephants as separate species. Here, for classifying is an adjective serving to describe support. Question: What KIND of support? Answer: support FOR CLASSIFYING.”
May 13, 2018
GMATGuruNY posted a reply to Sentence Correction Question in the Sentence Correction forum
“The SC above appears in GMATPrep. The OA is not C but D.”
May 12, 2018
GMATGuruNY posted a reply to A, B, C, D and E are 5 consecutive points on a straight in the Problem Solving forum
“AB = 5: https://s7.postimg.cc/qie6ijplj/ABCDE_1.png AC = 11: https://s7.postimg.cc/de8m615bb/ABCDE_2.png BC = 2CD: https://s7.postimg.cc/pu5bzcj3b/ABCDE_3.png DE = 4: https://s7.postimg.cc/fk2x04gd3/ABCDE_final.png Thus, AE = 5 + 6 + 3 + 4 = 18. The correct answer is D.”
May 12, 2018
GMATGuruNY posted a reply to The line represented by the equation y=4-2x is the in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the coordinates of point P. The slopes of perpendicular lines are NEGATIVE RECIPROCALS. Since y = -2x + 4 has a slope of -2, perpendicular line segment RP must have a slope of 1/2. Implication: When the correct answer is combined with the coordinates ...”
May 12, 2018
GMATGuruNY posted a reply to An escalator moves downward from street level to a subway in the Problem Solving forum
“DOWNWARD: When the escalator is turned OFF, the number of steps taken by Wesley to travel downward = 70. When the escalator is turned ON, the number of steps taken by Wesley to travel downward = 36, implying that the number of downward steps attributed to the escalator = 70-36 = 34. Implication: ...”
May 11, 2018
GMATGuruNY posted a reply to Twice the birds as last year will migrate to the in the Sentence Correction forum
“A: twice the birds as last year Here, BIRDS are illogically compared to LAST YEAR. Eliminate A. B: double the number...as last year Here, THE NUMBER is illogically compared to LAST YEAR. Eliminate B. C and E: that of last year''s Here that OF and last year''s both serve to convey ...”
May 11, 2018
GMATGuruNY posted a reply to Sentence Correction Question in the Sentence Correction forum
“A, B and C: three times AS many...charge under $8000 a year THAN In these options, than is unidiomatic. Correct: as many X AS Y. Eliminate A, B and C. Only PARALLEL FORMS may be compared. E: three times as many...CHARGE under $8000...as those CHARGING over $16,000. Here, charge is a VERB, ...”
May 11, 2018
GMATGuruNY posted a reply to If the terms of a sequence {An} are defined by An=n/100, whe in the Problem Solving forum
“For any EVENLY SPACED SET: Count = (biggest - smallest)/(increment) + 1. Average = (biggest + smallest)/2. Sum = (count)(average). The INCREMENT is the difference between successive values. Integers between 101 and 200, inclusive: Here, the integers are CONSECUTIVE, so the increment = ...”
May 11, 2018
GMATGuruNY posted a reply to The sum S of the arithmetic sequence a, a+d, a+2d,..., a+(n- in the Problem Solving forum
“For any EVENLY SPACED SET: Count = (biggest - smallest)/(increment) + 1. Average = (biggest + smallest)/2. Sum = (count)(average). The INCREMENT is the difference between successive values. Integers between 1 and 100, inclusive: Here, the integers are CONSECUTIVE, so the increment = 1. ...”
May 11, 2018
GMATGuruNY posted a reply to (2^5+2^6+2^7+2^8)^2=? in the Problem Solving forum
“(2⁵ + 2⁶ + 2⁷ + 2⁸)² = E.”
May 10, 2018
GMATGuruNY posted a reply to The probability of shooting a target increases after a in the Problem Solving forum
“Test an EASY CASE. Let: S = the original probability of shooting the target NS = the original probability of NOT shooting the target New S = the new probability of shooting the target New NS = the new probability of NOT shooting the target Case 1: Let NEW NS = 0.1, implying that the NEW S = ...”
May 10, 2018
GMATGuruNY posted a reply to abc0 is a positive, four-digit integer, where a, b and c are in the Data Sufficiency forum
“An integer is divisible by 4 only if its last two digits form a multiple of 4. For example: 93724 is divisible by 4 because its last two digits -- 2 and 4 -- form 24, which is a multiple of 4. Question stem, rephrased: Is the integer c0 a multiple of 4? Statement 1: No information about c. ...”
May 10, 2018
GMATGuruNY posted a reply to The original price of a certain Television set is discounted in the Problem Solving forum
“Let P = 100 and x = 10, implying that 2x = 20. Price after an x% discount = 100 - (10% of 100) = 100 - 10 = 90. Price after a 2x% discount = 90 - (20% of 90) = 90 - 18 = 72. The correct answer must yield a resulting price of $72 when x=10. Only B works: 100(1 - 0.03*10 + 0.0002*10²) = 100(1 ...”
May 10, 2018
GMATGuruNY posted a reply to Three friends rented a car for a week and divided the cost e in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the total cost. When the correct answer is plugged in, increasing the number of friends from 3 to 4 will reduce the cost per person by $15. Since the total cost is divided equally among 3 or 4 friends, the correct answer is almost certainly a multiple ...”
May 10, 2018
GMATGuruNY posted a reply to OG Two works published in 1984 in the Reading Comprehension forum
“golden age = a period when something was the most successful. From the passage: Women also gained power in comparison with their previous status, owning a higher proportion of real estate, for example. In contrast, Buel and Buel’s biography provides ample raw material for questioning the myth, ...”
May 9, 2018
GMATGuruNY posted a reply to Data Sufficiency Problem in the Data Sufficiency forum
“Since the average price = 141, one price must be LESS than 141, while the other price must be GREATER than 141. Statement 1: Model P sold for $30 less than Model Q. Thus, p< 141, while q>141. Check the ONLY case that also satisfies statement 2: Case 1: p=120 and q=150. To evaluate ...”
May 9, 2018
GMATGuruNY posted a reply to x and y are positive integers. If p and q are diff in the Data Sufficiency forum
“To determine the number of positive factors of an integer: 1) Prime-factorize the integer 2) Add 1 to each exponent 3) Multiply For example: 72 = 2³ * 3². Adding 1 to each exponent and multiplying, we get (3+1)*(2+1) = 12 factors. Here''s why: To determine how many factors ...”
May 9, 2018
GMATGuruNY posted a reply to If snow accumulation increased at a constant rate of 30 mill in the Problem Solving forum
“(1 millimeter accumulation) * (1 hour)/(30 millimeters accumulation) * (3600 seconds)/(1 hour) = 3600/30 = 120 seconds. In the equation above, all of the colored measurments CANCEL OUT, leaving the answer in terms of seconds. The correct answer is E.”
May 9, 2018
GMATGuruNY posted a reply to When a=x+(1/x) and b=x-(1/x), what is a^2 – b^2? in the Problem Solving forum
“Let x=1, with the following results: a = 1 + (1/1) = 2. b = 1 - (1/1) = 0. a² - b² = 2² - 0² = 4. When x=1, the correct answer must yield a value of 4. Only E is viable. The correct answer is E.”
May 9, 2018
GMATGuruNY posted a reply to Mr. and Mrs. Wiley have a child every J years. Their oldest in the Problem Solving forum
“Let J=2. Let 2000 = year in which the first child is born. Let now = 2006. Since a child is born every 2 years, there are now 4 children -- born in 2000, 2002, 2004 and 2006 -- and the oldest age is T=6. When a child is born 2 years from now, the number of children = 5. This is our target. ...”
May 9, 2018
GMATGuruNY posted a reply to Modifier in the Sentence Correction forum
“I share your concern about the OA. Please revisit my previous post, which has been revised to express the reasons for my concern.”
May 8, 2018
GMATGuruNY posted a reply to Which of the following is equal to 2^{k-1}3^{k+1}? in the Problem Solving forum
“Let k=1: $${2^{k-1}3^{k+1}} = {2^{1-1}3^{1+1}} = {2^{0}3^{2}} = 1*9 = 9.$$ Now plug k=1 into the answers to see which yields a value of 9. Only B works: 3²6^(k-1) = 9*6⁰ = 9*1 = 9. The correct answer is B.”
May 8, 2018
GMATGuruNY posted a reply to At the end of each year, the value of a certain antique watc in the Problem Solving forum
“Let k=1 and c=200%, implying that the value of the $1 watch increases by 200% each year. Value in 1993 = 1 + (200/100)(1) = 3. m = value in 1994 = 3 + (200/100)(3) = 9. Value in 1995 = 9 + (200/100)(9) = 27. This is our target. Now plug k=1 and m=9 into the answers to see which yields our ...”
May 8, 2018
GMATGuruNY posted a reply to A finite sequence {An} is arithmetic. If each term An of the in the Data Sufficiency forum
“An arithmetic sequence is an EVENLY SPACED SET. In an evenly spaced set, AVERAGE = MEDIAN. Question stem, rephrased: Is the median of the set even? Statement 1: Case 1: {0, 2} In this case, the median of the set is 1, so the answer to the rephrased question stem is NO. Case 2: {0, 2, 4} In ...”
May 7, 2018
GMATGuruNY posted a reply to If 5m=25^{2n}, what is the value of m, in terms of n? in the Problem Solving forum
“Let n = 1/2. Substituting n = 1/2 into 5m = 25^(2n), we get: 5m = 25¹ m = 5. The question stem asks for the value of m (5). Now plug n = 1/2 into the answers to see which yields the target value of 5. Only C works: m = 5^(4n-1) = 5¹ = 5. The correct answer is C.”
May 7, 2018
GMATGuruNY posted a reply to If a car went the first third of the distance at 80 kmh in the Problem Solving forum
“Let each third of the distance = 240 km, implying that the total distance = 3*240 = 720 km. Since the rate for the first third = 80 kmh, the time to travel the first third = d/r = 240/80 = 3 hours. Since the rate for the second third = 24 kmh, the time to travel the second third = d/r = 240/24 = ...”
May 6, 2018
GMATGuruNY posted a reply to W, X, Y and Z each represent a different number in the Problem Solving forum
“Sum of all 4 rows = 3 + 6 + 9 + 0 = 18. Sum of all 4 columns = -2 + 7 + n + 5 = n + 10. The values in blue must be EQUAL, since each represents the sum of all 16 values in the table. Thus: n+10 = 18 n=8. The correct answer is C.”
May 6, 2018
GMATGuruNY posted a reply to Modifier in the Sentence Correction forum
“A conjunction such as and must serve to connect PARALLEL FORMS. A and D: forms...and lowering In these options, forms (verb) and lowering (modifier) are not parallel forms. Eliminate A and D. C: forming...and lowers Here, forming (modifier) and lowers (verb) are not parallel forms. Eliminate ...”
May 6, 2018
GMATGuruNY posted a reply to Is x greater than zero? in the Data Sufficiency forum
“Each statement implies that x is NONZERO, with the result that any EVEN POWER of x will yield a POSITIVE value. Thus, we can simplify the inequalities by dividing each side by x². Statement 1: x⁶ > x² x⁶/x² > x²/x² x⁴ > 1. The resulting inequality requires that x>1 or ...”
May 6, 2018
GMATGuruNY posted a reply to Jacob drove from Town A to Town B at an average rate of in the Problem Solving forum
“Let the distance = 12 miles. Let x = 2 miles per hour, y = 3 miles per hour, and z = 6 miles per hour. Total time for the 3 trips = 12/2 + 12/3 + 12/6 = 12 hours. Average rate for the 3 trips = (total distance)/(total time) = (12+12+12)/12 = 3 miles per hour. This is our target. Now we ...”
May 6, 2018
GMATGuruNY posted a reply to The remainder, when a number n is divided by 6, is p. in the Data Sufficiency forum
“Statement 1: Case 1: n=8 Since n/6 = 8/6 = 1 R2, p=2. Since n/12 = 8/12 = 0 R8, q=8. In this case, p<q, with the result that the answer to the question stem is YES. Case 2: n=16 Since n/6 = 16/6 = 2 R4, p=4. Since n/12 = 16/12 = 1 R4, q=4. In this case, p=q, with the result that the ...”
May 6, 2018
GMATGuruNY posted a reply to A rectangular box is 10 inches wide, 10 inches long in the Problem Solving forum
“The longest line that can be drawn inside a rectangular solid is called the MAIN DIAGONAL. Use the SUPER-PYTHAGOREAN THEOREM. If d = the length of the main diagonal, then: d² = l² + w² + h². In the problem above: d² = 10² + 10² + 5² d² = 225 d = 15. The correct answer is ...”
May 6, 2018
GMATGuruNY posted a reply to If n is an integer between 10 and 99, is n < 80? in the Data Sufficiency forum
“Statement 1: Case 1: n = 11, with the result that the sum of the two digits of n = 1+1 = 2 In this case, n < 80, so the answer to the question stem is YES. Case 2: n = 83, with the result that the sum of the two digits of n = 8+3 = 11 In this case, n > 80, so the answer to the question ...”
May 6, 2018
GMATGuruNY posted a reply to In an experiment, two different types of recorded in the Critical Reasoning forum
“Experiment: In nursery A, classical music was played; in nursery B, rock music was played. Result: The babies in nursery A cried less, suffered fewer minor ailments, and gained more weight than did the babies in nursery B. Implied conclusion: The babies in nursery A had better outcomes ...”
May 5, 2018
GMATGuruNY posted a reply to In a room filled with 7 people, 4 people phave exactly 1 in the Problem Solving forum
“Let''s say that the 7 people are ABCDEFG. 4 people have exactly 1 sibling: Let''s say that A and B are siblings and that C and D are siblings. This means: A has 1 sibling (B). B has 1 sibling (A). C has 1 sibling (D). D has 1 sibling (C). 3 people have exactly 2 siblings: Let''s say ...”
May 5, 2018
GMATGuruNY posted a reply to If x is the sum of the first 10 positive multiples of 3 and in the Problem Solving forum
“For any EVENLY SPACED SET: AVERAGE = (BIGGEST + SMALLEST)/2. SUM = (COUNT)(AVERAGE). The first 10 positive multiples of 3 are as follows: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30. Thus: Average = (biggest + smallest)/2 = (30+3)/2 = 16.5. x = sum = (count)(average) = 10*16.5 = 165. The first ...”
May 4, 2018
GMATGuruNY posted a reply to What is the largest integer if the sum of three consecutive in the Problem Solving forum
“Consecutive even integers constitute an EVENLY SPACED SET. For any evenly spaced set, MEDIAN = AVERAGE. In the problem at hand: Median = Average = 318/3 = 106. Since the median of the 3 consecutive even integers = 106, the greatest of the 3 consecutive even integers = 108. The correct answer ...”
May 4, 2018
GMATGuruNY posted a reply to Harold works at a resort from the beginning of March to the in the Problem Solving forum
“Excluding August, let the average earned each month = $1, implying that the total earned for the 6 non-August months = 6*1 = $6. Since 3 times the average is earned in August, the amount earned in August = 3*1 = $3, bringing the total earnings to $9. Resulting fraction: August/Total = 3/9 = 1/3. ...”
May 3, 2018
GMATGuruNY posted a reply to If x and y are two different integers, is |x|=|y|? in the Data Sufficiency forum
“Case 1: y=0, with the result that x = y+2 = 0+2 = 2 In this case, |x|=2 and |y|=0, so the answer to the question stem is NO. Case 2: y=-1, with the result that x = y+2 = -1+2 = 1 In this case, |x|=1 and |y|=1, so the answer to the question stem is YES. Since the answer is NO in Case 1 but YES in ...”
May 3, 2018
GMATGuruNY posted a reply to A group of 8 friends want to play doubles tennis. in the Problem Solving forum
“Since there are 8 people, the first friend selected can be paired with 7 different people, yielding 7 possible pairs. Since 6 people remain, the next friend selected can be paired with 5 different people, yielding 5 possible pairs. Since 4 people remain, the next friend selected can be paired ...”
May 3, 2018
GMATGuruNY posted a reply to There are three blue marbles, three red marbles, and three in the Problem Solving forum
“P(good outcome) = P(one way) * total possible ways. Let B = blue and R = red. P(one way): One way to select exactly 1 blue marble and 2 red marbles is BRR. P(B on the 1st pick) = 3/9. (Of the 9 marbles, 3 are blue.) P(R on the 2nd pick) = 3/8. (Of the 8 remaining marbles, 3 are red.) P(R ...”
May 3, 2018
GMATGuruNY posted a reply to How many odd three-digit integers greater than 800 are there in the Problem Solving forum
“Case 1: Hundreds digit = 8 Number of options for the units digit = 5. (Any of the 5 odd digits.) Number of options for the tens digit = 8. (Of the 10 digits, any but the two already used.) To combine the options above, we multiply: 5*8 = 40. Case 1: Hundreds digit = 9 Number of options for ...”
May 3, 2018
GMATGuruNY posted a reply to If x is a positive integer, is x/30 a terminating decimal? in the Data Sufficiency forum
“A TERMINATING decimal has a FINITE NUMBER OF DIGITS: .5 .123 .8730253. A NON-TERMINATING decimal has an INFINITE NUMBER OF DIGITS: .33333.... .121212.... .871871871... To determine whether a fraction will yield a terminating decimal: 1. Put the fraction in its MOST REDUCED FORM. 2. ...”
May 3, 2018
GMATGuruNY posted a reply to How many multiples of 4 lie between 4^4 and 4^5, inclusive? in the Problem Solving forum
“The positive multiples of 4 constitute an EVENLY SPACED SET. For any evenly spaced set: Number of values = (biggest - smallest)/increment + 1. The INCREMENT is the distance between one term and the next. The positive multiple of 4 have an increment of 4. Thus: Number of multiples of 4 ...”
May 3, 2018
GMATGuruNY posted a reply to The distance between Alice’s house and Bob's is 120 miles. in the Problem Solving forum
“Total distance between Alice and Bob =120 miles. Since Alice travels 40 miles from her home to meet Bob, Bob travels the remaining 80 miles. Since Bob travels twice as far as Alice, his rate is twice Alice''s rate. Since Alice''s rate = x miles per hour, Bob''s rate = 2x miles per hour. The ...”
May 2, 2018
GMATGuruNY posted a reply to Jane and Ashley take 20 days and 40 days respectively to in the Problem Solving forum
“Let the job = the LCM of 20 and 40 = 40 units. Since Jane takes 20 days to produce the 40-unit job, Jane''s rate = w/r = 40/20 = 2 units per day. Since Ashley takes 40 days to produce the 40-unit job, Jane''s rate = w/r = 40/40 = 1 unit per day. During Jane''s 8-day break, Ashely works alone ...”
May 1, 2018
GMATGuruNY posted a reply to John and Amanda stand at opposite ends of a straight road in the Problem Solving forum
“All possible outcomes: Number of possible rates for John = 4. Number of possible rates for Amanda = 4. To combine the number of rate options for John with the number of rate options for Amanda, we multiply: 4*4 = 16. Good outcomes: John will travel farther than Amanda if his rate is greater ...”
April 30, 2018
GMATGuruNY posted a reply to On the number line, 0 lies between x and y. Is x>y? in the Data Sufficiency forum
“Since 0 lies between x and y, x and y have DIFFERENT SIGNS. Statement 1: The distance between x and 0 is 2 times the distance between y and 0 Thus: |x| = 2|y| Case 1: y=1, implying that |x| = 2 Since x have must have different sign from y, x=-2. In this case, x < y, so the answer to the ...”
April 30, 2018
GMATGuruNY posted a reply to If p and q are positive integers such in the Data Sufficiency forum
“pq will have 4 distinct positive factors in the following cases: Case 1: pq = a³, where a is a prime number. Case 2: pq = ab, where a and b are distinct prime numbers. Examples of Case 1: pq = 2³ = 8, with the result that pq has factors 1, 2, 4 and 8. pq = 3³ = 27, with the result that pq ...”
April 30, 2018
GMATGuruNY posted a reply to If the profit on a product is 20 percent of its sales price, in the Problem Solving forum
“Let the sale price = 100, implying that the profit = 0.2(100) = 20 and that the cost price = (sale price) - (profit) = 100-20 = 80. What percent of the cost price is the profit? profit/cost = 20/80 = 1/4 = 25%. The correct answer is B.”
April 30, 2018
GMATGuruNY posted a reply to Double matrix method in the Data Sufficiency forum
“To organize the data, use the following DOUBLE-MATRIX: https://s31.postimg.cc/yinkrxs7b/matrix_tennis_and_swimming_statement_0.png To answer the question stem, we need to determine the values in the two boxes with question marks (tennis but not swimming, swimming but not tennis). Statement ...”
April 30, 2018
GMATGuruNY posted a reply to A lighting store is stocked with 410 fixtures. Some of the in the Problem Solving forum
“The expression in blue represents the total number of imported lamps. Since x/4 is being SUBTRACTED, the expression will be minimized if x/4 is AS GREAT AS POSSIBLE. Since x must be less than or equal to the total number of fixtures -- 410 -- the greatest possible integer value for x/4 will be ...”
April 28, 2018
GMATGuruNY posted a reply to A lighting store is stocked with 410 fixtures. Some of the in the Problem Solving forum
“5% of the floor lamps are imported. 5% = 5/100 = 1/20. Since 1/20 of the floor lamps are imported, the total number of floor lamps must be a MULTIPLE OF 20. 30% of the table lamps are imported. 30% = 30/100 = 3/10. Since 3/10 of the table lamps are imported, the total number of table lamps ...”
April 28, 2018
GMATGuruNY posted a reply to Given that N=a3b4c5 where a, b and c are distinct prime in the Problem Solving forum
“The problem should read as follows: The exponent for a perfect square must be a MULTIPLE OF 2. The exponent for a perfect cube must be a MULTIPLE OF 3. The exponent for a perfect fifth must be a MULTIPLE OF 5. Thus, the exponent for an integer that is a perfect square, a perfect cube and a ...”
April 28, 2018
GMATGuruNY posted a reply to Is xy< 10? in the Data Sufficiency forum
“Statements combined: If x=0 and y=0, then xy = 0, so the answer to the question stem is YES. If x=-10 and y=-10, then xy = 100, so the answer to the question stem is NO. Since the answer is YES in the first case but NO in the second case, the two statements combined are INSUFFICIENT. The ...”
April 28, 2018
GMATGuruNY posted a reply to Is p^2 - 1 divisible by 12? in the Data Sufficiency forum
“Question stem, rephrased: Is (p+1)(p-1) divisible by 12? Statement 1: Case 1: p=4 In this case, (p+1)(p-1) = 5*3 = 15, so the answer to the question stem is NO. Case 2: p=5 In this case, (p+1)(p-1) = 6*4 = 24, so the answer to the question stem is YES. Since the answer is NO in Case 1 but ...”
April 28, 2018
GMATGuruNY posted a reply to If −2 < x ≤ 1/2 and 7< y ≤ 10...... in the Problem Solving forum
“Since y is POSITIVE and x² must be NONNEGATIVE, only two cases are possible: Case 1: yx² = (positive)(0) = 0. Case 2: yx² = (positive)(positive) = positive. Case 1 is possible if y=8 and x=0. Thus, the least possible value for yx² is 0. The correct answer is C.”
April 28, 2018
GMATGuruNY posted a reply to If x + z = 8, 2y + z =11, and 3x + y= 19, what is the in the Problem Solving forum
“One approach: Subtracting x+z = 8 from 2y+z = 11, we get: (2y+z) - (x+z) = 11-8 2y - x = 3 2y - 3 = x. Substituting x = 2y-3 into 3x+y = 19, we get: 3(2y-3) + y = 19 6y - 9 + y = 19 7y = 28 y = 4. Substituting y=4 into 2y + z = 11, we get: (2*4) + z = 11 z = 3. Substituting z=3 ...”
April 28, 2018
GMATGuruNY posted a reply to If x y and z are positive is xz = 7xy? in the Data Sufficiency forum
“Since x is positive, we can divide both sides of the question stem by x: xz/x = 7xy/x z =7y. Questions stem, rephrased: Does z = 7y? Statement 1: z/y = 7 z = 7y. Thus, the answer to the question stem is YES. Statement 2: No information about z. INSUFFICIENT. The correct answer is ...”
April 28, 2018
GMATGuruNY posted a reply to If n = (33)^43 + (43)^33 what is the units digit of n? in the Problem Solving forum
“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 3 = 9*3 = 27.) 3⁴ --> units digit of 1. (Since the product of the preceding units ...”
April 28, 2018
GMATGuruNY posted a reply to Z is 120% of Y. X is smaller than Z by 80%. What percentage in the Problem Solving forum
“Since Z is 120% of Y, we get: Z/Y = 120/100 = 6/5. X is 80% less than Z implies that X is 20% of Z: X/Z = 20/100 = 1/5. What percentage of Y is X? X/Y = X/Z * Z/Y = 1/5 * 6/5 = 6/25 = 24/100. Thus: X is 24% of Y. The correct answer is E.”
April 27, 2018
GMATGuruNY posted a reply to NOT true in the Problem Solving forum
“If -14 < a-b < 8 (option B) is multiplied by -1, we get: 14 > -a+b > -8 14 > b-a > -8 -8 < b-a < 14. Implication: If B is true, then C is NOT true, since C indicates that -7 < b-a < 14. In other words: B and C cannot both be true. Test whether B or C is true. ...”
April 27, 2018
GMATGuruNY posted a reply to Lightbox, Inc., owns almost all of the movie theaters in in the Critical Reasoning forum
“Premises: Attendance at Lightbox''s theaters is only just large enough for profitability now, and the county''s population is not expected to increase over the next ten years. Conclusion: The plan to double the number of screens will not prove profitable. To weaken the conclusion, the correct ...”
April 27, 2018
GMATGuruNY posted a reply to If g is a function defined for all x by g(x)=(x^4)/16 in the Problem Solving forum
“Let x=2, with the result that g(x) = g(2) = 2⁴/16 = 1. The question stem asks for the value of g(2x): g(2x) = g(2*2) = g(4) = 4⁴/16 = (16*16)/16 = 16. Now plug g(x) = 1 into the answers to see which yields the target value of 16 for g(2x). Only E works: 16g(x) = 16*1 = 16. The correct ...”
April 27, 2018
GMATGuruNY posted a reply to If y = 3x, then the value of 10% of y is in the Problem Solving forum
“Let x=10 and y = 3x = 3*10 = 30. The question stem asks for the value of 10% of y: 10% of y = (10/100)(30) = 3. Now plug x=10 into the answers to see which yields the target value of 3. Only B works: 0.3x = 0.3(10) = 3. The correct answer is B. Algebra: Since y = 3x, we get: 10% of y = ...”
April 27, 2018
GMATGuruNY posted a reply to Machine A and machine B process the same work at different in the Problem Solving forum
“Machine D processes work three times as fast as Machine C. Machine D’s work rate is also exactly four times Machine B’s rate. Let D = 12 units per minute, implying that C= 4 units per minute and B = 3 units per minute. Machine C processes work as fast as Machines A and B combined. Since C ...”
April 26, 2018
GMATGuruNY posted a reply to The pesticide Azocide, introduced to central valley farms in the Sentence Correction forum
“because + NO OF must be followed by a CLAUSE. A: because other pesticides...neutralizing its desired effect. Here, the red portion after because lacks a verb and thus does not constitute a clause. Eliminate A. B: The pesticide Azocide has become ineffective...because of the chemical ...”
April 26, 2018
GMATGuruNY posted a reply to Overuse of antibiotics often leads to a reduction in the in the Sentence Correction forum
“B and C: If overused, one theory Here, overused seems to refer to theory, implying that ONE THEORY might be OVERUSED. This meaning is nonsensical. The intended meaning of the original sentence is that ANTIBIOTICS might be overused. Eliminate B and C. D: The observation...has recently given ...”
April 26, 2018
GMATGuruNY posted a reply to The students at a school took a math exam. Is the average (a in the Data Sufficiency forum
“Statement 1: No information about the median. INSUFFICIENT. Statement 2: Let the total number of scores = 100. Since 51 of the 100 scores are greater than the average, the 50th highest score and the 51st highest score are both greater than the average. Thus, the median score -- which is ...”
April 25, 2018
GMATGuruNY posted a reply to A bag contains only black and white balls. What is the proba in the Data Sufficiency forum
“Question stem, rephrased: What fraction of the balls are black? Statement 1: The total number of balls in the bag is 12 No information about what fraction of the balls are black. INSUFFICIENT. Statement 2: The number of white balls is 3 times the number of black balls Of every 4 balls, 3 ...”
April 25, 2018
GMATGuruNY posted a reply to Alice sells apples. She sold at least 10 lb every day last w in the Problem Solving forum
“Since at least 10 apples are sold every day, the least number of apples sold on a single day = 10. The maximize the range, we must maximize the GREATEST number of apples sold on a single day. To maximize the greatest number of apples sold on a single day, we must MINIMIZE the number of apples sold ...”
April 25, 2018
GMATGuruNY posted a reply to It takes Kaya a total of 9 hours to go from home to work in the Problem Solving forum
“Time and rate have a RECIPROCAL RELATIONSHIP: If John''s time is twice Mary''s time, then John''s rate is 1/2 Mary''s rate. Here, the rate for the return trip is twice the rate for the trip to work, implying that the time for the return trip is 1/2 the time for the trip to work. Since the total ...”
April 24, 2018
GMATGuruNY posted a reply to Alice and Bruce each bought a refrigerator, and the sum of in the Problem Solving forum
“Let A = Alice''s amount and B = Bruce''s amount. Twice of what Alice paid was $75 more than what Bruce paid. Since twice Alice''s amount is equal to $75 more than Bruce''s amount, we get: 2A = 75 + B 2A - 75 = B. The sum of their purchases was $900. Thus, the two blue values above must sum ...”
April 24, 2018
GMATGuruNY posted a reply to Set T consists of 82 consecutive odd integers. If the sum of in the Problem Solving forum
“For any set of consecutive integers: SUM = (COUNT)(MEDIAN). In the problem above: SUM = 3⁸ - 165 = (3⁴3⁴) - 165 = (81*81) - 165 = (integer with a units digit of 1) - (integer with a units digit of 5) = integer with a units digit of 6. COUNT = 82 integers. Since the sum has a units ...”
April 24, 2018
GMATGuruNY posted a reply to P persons have decided to rent a van to tour while on in the Problem Solving forum
“Let x = $10 and P = 10 people. Since 10 people plan to split the $10 cost, the expected cost per person = (total cost)/(number of people) = 10/10 = $1. Let D=9, implying that 9 of the 10 people cancel, with the result that the one remaining person must pay the entire $10. Since the one remaining ...”
April 24, 2018
GMATGuruNY posted a reply to OG In the Sonoran Desert of northwestern Mexico in the Reading Comprehension forum
“From the passage: During spring in the Sonoran Desert...diurnal cactus-pollinating birds are significantly more abundant. Compared with the Sonoran Desert''s cardon and saguaro, columnar cacti in southern Mexico produce far fewer flowers per night, with the result that bats are able to pollinate ...”
April 24, 2018
GMATGuruNY posted a reply to OG In the Sonoran Desert of northwestern Mexico in the Reading Comprehension forum
“From the passage: Pollinators can be unreliable for several reasons. They may be dietary specialists, but their abundance may be chronically low relative to the availability of flowers. Nectar-feeding bats...being unreliable cactus-flower pollinators, and daytime pollinators more abundant and ...”
April 24, 2018
GMATGuruNY posted a reply to What is the value of x? \(|x+2|+|x-3| = |2x+3|\) in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the value of x. E: x=7 Substituting x=7 into |x+2|+|x-3|=|2x+3|, we get: |7+2|+|7-3|=|2*7 + 3| 9 + 4 = 17 13 = 17. Doesn''t work. Eliminate E. D: x=4 Substituting x=4 into |x+2|+|x-3|=|2x+3|, we get: |4+2|+|4-3|=|2*4 + 3| 6 + 1 = 11 7 = ...”
April 23, 2018
GMATGuruNY posted a reply to How many positive integers less than 60 are equal to in the Problem Solving forum
“An even multiple of 5 is divisible by 2 and 5. Any integer divisible by 2 and 5 is a MULTIPLE OF 10. The following multiples of 10 are less than 60: 10, 20, 30, 40, 50. Total options = 5. The correct answer is B.”
April 23, 2018
GMATGuruNY posted a reply to If n is an integer, is n - 1 even? in the Data Sufficiency forum
“If n-1 is even, we get the following options for n-1: n-1 = 0, 2, 4, 6, 8, 10, 12... Adding 1 to every value in the list above, we get the following options for n: n = 1, 3, 5, 7, 9, 11, 13.... The resulting list indicates that n-1 will be even if N IS ODD. Question stem, rephrased: Is n odd? ...”
April 23, 2018
GMATGuruNY posted a reply to If a continuous cable 10m long was marked off at intervals in the Problem Solving forum
“The length of the cable can be ANY VALUE. To make the math easier, let the length of the cable = the product of the two denominators = 4*5 = 20 meters. When the cable is divided into 4ths, markings are yielded at 5, 10, and 15: ...”
April 23, 2018
GMATGuruNY posted a reply to og210 in the Sentence Correction forum
“The blue portion constitutes the core of the sentence. The green portion is a RESTRICTIVE modifier serving to describe a giant fungus. Generally, a restrictive modifier is considered ESSENTIAL: it cannot be omitted without a loss of meaning. If the green portion here were omitted, a reader would ...”
April 22, 2018
GMATGuruNY posted a reply to Evaluate the Argument............OG Diagnostic test in the Critical Reasoning forum
“The statements above are all reasonable.”
April 22, 2018
GMATGuruNY posted a reply to Numbers a and b are positive integers. If a^4-b^4 is divided in the Data Sufficiency forum
“a⁴-b⁴ = (a²+b²)(a²-b²) = (a²+b²)(a+b)(a-b). Statement 1: Since a+b is divisible by 3, (a²+b²)(a+b)(a-b) is divisible by 3. Thus, dividing a⁴-b⁴ by 3 will yield a remainder of 0. SUFFICIENT. Statement 2: In other words, a²+b² is 2 more than a multiple of 3: a²+b² = 3k ...”
April 22, 2018
GMATGuruNY posted a reply to Percentage change in the Problem Solving forum
“The question stem asks for the percent change in the following RATIO: (royalty percentage) : (number of copies).'' Initial ratio = 10 : 10,000. New ratio = 12 : 15,000. From 10/10000 to 12/15000 = a 20% DECREASE. In your solution, you calculate the percent change only for the values in red: ...”
April 21, 2018
GMATGuruNY posted a reply to Five digit combination problem in the Problem Solving forum
“A five-digit integer formed from the five given digit options will be divisible by 2 and/or 5 if its units digit is 0, 2, 4 or 5. Thus: Number of options for the units place = 4. (0, 2, 4, or 5). Number of options for the ten-thousands place = 4. (Any of the 5 digits except 0.) Number of options ...”
April 21, 2018
GMATGuruNY posted a reply to OG In the Sonoran Desert of northwestern Mexico in the Reading Comprehension forum
“Yet the flowers of the Sonoran Desert cacti have EVOLVED to remain open after sunrise, allowing pollination by such diurnal visitors as bees and birds. Why have these cacti expanded their range of pollinators by remaining open and receptive in daylight? The rest of the passage attempts to answer ...”
April 21, 2018
GMATGuruNY posted a reply to Evaluate the Argument............OG Diagnostic test in the Critical Reasoning forum
“This line of reasoning is correct.”
April 21, 2018
GMATGuruNY posted a reply to Percentage change in the Problem Solving forum
“Since the question stem asks for a PERCENT CHANGE, we can make the math easier by using easier values. The percent change will remain constant as long as the first set of copies and the second set of copies are in the following ratio: 10000:15000 = 10:15. Thus, the prompt can be rephrased as ...”
April 21, 2018
GMATGuruNY posted a reply to Is ∣x∣<1 ? in the Data Sufficiency forum
“Statement 1: Since the square of a value must be NONNEGATIVE, y² ≥ 0. If y²=0, then x = 1/3. If y²>0, then x = 1/(more than 3), implying that x < 1/3. Since x≤1/3, the answer to the question stem is YES. SUFFICIENT. Statement 2: No information about x. INSUFFICIENT. The ...”
April 20, 2018
GMATGuruNY posted a reply to Does x = 3? in the Data Sufficiency forum
“Statement 1: (x−3)(y−1) = 0 If y-1=0 -- implying that y=1 -- then x-3 can be equal to ANY VALUE. For example: x=3 and y=1, with the result that (x-3)(y-1) = (3-3)(1-0) = 0*0 = 0. x=4 and y=1, with the result that (x-3)(y-1) = (4-1)(1-0) = 3*0 = 0. Since the answer to the question stem is ...”
April 20, 2018
GMATGuruNY posted a reply to If k is a positive two-digit integer, what is the tens in the Data Sufficiency forum
“Statement 1: Case 1: k=14, with the result that the tens digit of k is 1 Case 2: k=23, with the result that the tens digit of k is 2 Since the tens digit can be different values, INSUFFICIENT. Statement 2: Make a list of option for k+6: k+6 = 30, 31, 32, 33, 34, 35, 36, 37, 38, 39. To yield ...”
April 20, 2018
GMATGuruNY posted a reply to If a > 0 and b > 0, is a/b > b/a ? in the Data Sufficiency forum
“Is a/b > b/a? Since a and b are both positive, we can CROSS-MULTIPLY and take the square root of both sides: a² > b². a > b. Question stem, rephrased: Is a > b? Statement 1: a = b-2 Since a is 2 less than b, the answer to the question stem is NO. SUFFICIENT. Statement 2: ...”
April 20, 2018
GMATGuruNY posted a reply to Is kw>0? in the Data Sufficiency forum
“Statement 1: Case 1: k=10 and w=0 In this case, kw=0, so the answer to the question stem is NO. Case 2: k=11 and w=1 In this case, kw=11, so the answer to the question stem is YES. Since the answer is NO in Case 1 but YES in Case 2, INSUFFICIENT. Statement 2: Case 3: k=0 and w=0 In this ...”
April 20, 2018
GMATGuruNY posted a reply to a percent of b is c and c percent of d is e, then a is what in the Problem Solving forum
“a percent of b is c Let a=b=c=100. since 100% of 100 is 100. c percent of d is e. Let c=d=e=100. since 100% of 100 is 100. a is what percent of e? Since a=e=100, a is 100% of e. The correct answer must yield the value in blue when b=d=100 is plugged in. Only E works: 1000000/bd = ...”
April 20, 2018
GMATGuruNY posted a reply to GMATPrep EP2: One key to predicting a competitor's in the Reading Comprehension forum
“From the passage: The dominant player, as the target of consumer backlash, introduced a variety of foods it promoted as healthy, The other, foreseeing this move, saw an opportunity to find market share in the less health-conscious fast-food segment and so introduced high-fat, high-calorie ...”
April 19, 2018
GMATGuruNY posted a reply to Jim takes a seconds to swim c meters at a constant rate in the Problem Solving forum
“Let c=6 meters, a=2 seconds, and b=1 second. Since Jim takes 2 seconds to travel the 6-meter distance, Jim''s rate = d/t = 6/2 = 3 meters per second. Since Roger takes 1 second to travel the 6-meter distance, Roger''s rate = d/t = 6/1 = 6 meters per second. When Jim and Roger travel toward each ...”
April 19, 2018
GMATGuruNY posted a reply to When a and b are positive integers, what is the greates in the Data Sufficiency forum
“Consecutive integers are COPRIMES: they share no factors other than 1. Statement 1: a=100, implying that a+100 = 100+100 = 200 Case 1: b=100, with the result that a+b = 100+100 = 200 The GCF for the value in blue (200) and Case 1 (200) is 200. Case 2: b=101, with the result that a+b = 100+101 ...”
April 19, 2018
GMATGuruNY posted a reply to What was the percent increase in the value of a certain in the Data Sufficiency forum
“If a value DOUBLES, then it increases by 100%: x + (100% of x) = x + x = 2x. Thus, Statement 2 indicates that the percent increase = 100. SUFFICIENT.”
April 18, 2018
GMATGuruNY posted a reply to A certain office supply store stocks 2 sizes of in the Problem Solving forum
“Case 1: The notepads are all of the same size and the same color Number of size options = 2. Number of color options = 4. To combine the options above, we multiply: 4*2 = 8. Case 2: The notepads are all of the same size but of 3 different colors Number of size options = 2. From the 4 ...”
April 18, 2018
GMATGuruNY posted a reply to In a certain coding scheme, each word is encoded by in the Data Sufficiency forum
“Question stem, rephrased: How are the four letters T, A, M and E encoded? Statement 1: Since MAT is encoded as DLX, we get the following chart: ACTUAL LETTER --> ENCODED LETTER M --> D A --> L T --> X No information about the how to encode the letter E. INSUFFICIENT. ...”
April 18, 2018
GMATGuruNY posted a reply to 200 is what percent of 40? in the Problem Solving forum
“To convert a fraction to a percent, multiply the fraction by 100. Question: x is what FRACTION y? Translation: x/y = ? Question: x is what PERCENT of y? Translation: x/y * 100 = ? Thus: 200 is what percent of 40? Translation: 200/40 * 100 = 5* 100 = 500. The correct answer is E.”
April 18, 2018
GMATGuruNY posted a reply to If q is a member of the set {21, 22, 24, 25, 26, 27} in the Data Sufficiency forum
“Statement 1: Here, there are exactly two options for q: Case 1: q=25, since the only prime factor of 25 is 5. Case 2: q=27, since the only prime factor of 27 is 3. Since q can be different values, INSUFFICIENT. Statement 2: Here, there are exactly two options for q: Case 2: q=27, since 27 ...”
April 18, 2018
GMATGuruNY posted a reply to If y is 80 percent greater than x, then x is what percent in the Problem Solving forum
“Let x = 100. Since y is 80% greater than x, y = 100 + (80/100)(100) = 180. x is what percent less than y? In other words: What is the percent decrease from y=180 to x=100? Percent decrease = Difference/Larger * 100 = (180-100)/180 * 100 = 4/9 * 100 = a bit less than 50%. The correct answer ...”
April 18, 2018
GMATGuruNY posted a reply to What is the value of the sum of a list of n odd integers? in the Data Sufficiency forum
“Each statement indicates the same information -- that there are 8 odd integers. Thus, both statements are satisfied by the following cases: Case 1: 1, 1, 1, 1, 1, 1, 1, 1 Case 2: 1, 1, 1, 1, 1, 1, 1, 3 In Case 1, the sum of the 8 odd integers = 8. In Case 2, the sum of the 8 odd integers = 10. ...”
April 18, 2018
GMATGuruNY posted a reply to If the average of p and 4p is 10, then p in the Problem Solving forum
“SUM/COUNT = AVERAGE In the problem above: Sum = p + 4p. Count = 2. Average = 10. Plugging these values into the equation in blue, we get: (4p + p)/2 = 10 5p = 20 p = 4. The correct answer is C.”
April 18, 2018
GMATGuruNY posted a reply to If a/b = 1/2, then the numerical value of which of the in the Problem Solving forum
“An alternate approach is to plug into the five answer choices two cases such that a/b = 1/2: Case 1: a=1 and b=2 Case 2: a=2 and b=4 Note: When the question stem includes the phrase which of the following, the correct answer is likely to be D or E. For this reason, we should start with answer ...”
April 17, 2018
GMATGuruNY posted a reply to When thw integer x is divided by the integer y, the in the Problem Solving forum
“When one positive integer is divided by another, we typically represent what''s left over either as a REMAINDER or as a DECIMAL. There is a relationship between the two representations: Remainder/Divisor = Decimal. When 5 is divided by 2: Remainder representation: 5/2 = 2 R1. Decimal ...”
April 17, 2018
GMATGuruNY posted a reply to Is x>0? in the Data Sufficiency forum
“In Statement 1, the only real solution is x ≈ 1/2, but Statement 2 requires that x<-1 or x>5. Since the two statements contradict each other, the problem is invalid.”
April 17, 2018
GMATGuruNY posted a reply to For the positive integers x, x + 2, x + 4, x + 7, and in the Problem Solving forum
“Let x=1, yielding the following set of values: x = 1 x+2 = 3 x+4 = 5 x+7 = 8 x+12 = 13. Mean = (1+3+5+8+13)/5 = 30/5 = 6. Median = 5. Mean - median = 6-5 = 1. The correct answer is B. Since only one answer choice can be correct, there is no need to test any other values for x.”
April 15, 2018
GMATGuruNY posted a reply to Every delegate to the convention is a party member. Some in the Critical Reasoning forum
“every = ALL. some = AT LEAST ONE. Given information: All delegates to the convention are party members. At least one delegate to the convention is a government official. All government officials at the convention speak at the convention. An alternate approach is to apply the NEGATION ...”
April 15, 2018
GMATGuruNY posted a reply to Nearly two tons of nuclear-reactor fuel in the Sentence Correction forum
“D: The chances...increase greatly with the...increasing amount. Here, increase and increasing are redundant. Eliminate D.”
April 15, 2018
GMATGuruNY posted a reply to Does ab = a^2 in the Data Sufficiency forum
“ab = a² 0 = a² - ab 0 = a(a-b). The resulting equation is valid only if a=0 or a=b. Question stem, rephrased: Does a=0 or a=b? Statement 1: If a=1 and b=1, then the answer to the rephrased question stem is YES. If a=1 and b=-1, then the answer to the rephrased question stem is NO. Since ...”
April 14, 2018
GMATGuruNY posted a reply to Alice is paid at a constant rate of $x per hour for the firs in the Problem Solving forum
“Since Alice works 8 hours after the first 40 hours, she works 8 hours at the $30 rate: 8*30 = 240. Remaining earnings = (total earnings) - (earnings for the last 8 hours) - 920-240 = 680. Since she works 40 hours to earn this $680, her regularly hourly rate = earnings/hours = 680/40 = 17. The ...”
April 14, 2018
GMATGuruNY posted a reply to p>q, Is q negative? in the Data Sufficiency forum
“Statement 1: Case 1: q=1 Substituting q=1 into pq + q² > 0, we get: p(1) + 1² > 0 p > -1. Since this case requires that p>-1, and the prompt requires that p>q, it''s possible that p=2. Thus, a valid combination for Statement 1 is p=2 and q=1, in which case the answer to the ...”
April 14, 2018
GMATGuruNY posted a reply to probability in the Problem Solving forum
“The portion in red is incorrect. From the 5 people, the number of ways to choose 2 = 5C2 = (5*4)/(2*1) = 10. Of the10 possible pairs, only 1 includes Amir and Brian. Thus, P(Amir and Brian are both selected) = 1/10. Alternate approach: P(Amir or Brian is selected on the first pick) = 2/5. ...”
April 14, 2018
GMATGuruNY posted a reply to A rocket soars for 12 seconds at 150 meters per second. in the Problem Solving forum
“Alternate approach: Lower rate = rate upward = 150 meters per second. Higher rate = rate downward = d/t = 600/3 = 200 meters per second. Since the rocket travels 12 seconds upward and 3 seconds downward, the time ratio for the two rates = (12 seconds) : (3 seconds) = 4:1. Implication: Of ...”
April 13, 2018
GMATGuruNY posted a reply to Each of the 50 students participating in a in the Data Sufficiency forum
“Statement 1: Since fewer than 1/2 of the students are female, the probability of picking a female graduate student must be less than 1/2. Thus, the answer to the question stem is YES. SUFFICIENT. Statement 2: Since fewer than 1/2 of the students are graduate students, the probability of ...”
April 13, 2018
GMATGuruNY posted a reply to Charlie drives 30 miles each way to work and back. in the Problem Solving forum
“Since the distance in each direction is the same, we can plug in ANY VALUE for the distance. Let the distance in each direction = the LCM of 40 and 20 = 40 miles. When Charlie travels the 40-mile distance at 40 mph, the time = d/r = 40/40 = 1 hour. When Charlie travels the 40-mile distance at 20 ...”
April 13, 2018
GMATGuruNY posted a reply to If x > y, is x > 6 ? (1) (x - 7)(y - 7) = 0 (2) x > in the Data Sufficiency forum
“Statement 1: (x - 7)(y - 7) = 0 Case 1: x=7 Here, the answer to the question stem is YES. Case 2: y=7 Substituting y=7 into x > y, we get: x > 7. Thus, the answer to the question stem is YES. Since the answer is YES in both cases, SUFFICIENT. Statement 2: x > 18 - 2y x + 2y > ...”
April 13, 2018
GMATGuruNY posted a reply to Frieda walks 6 feet per second, a pace which is 1/3 as in the Problem Solving forum
“Since Frieda''s rate is 1/3 Evita''s rate, Evita''s rate is 3 times Frieda''s rate: 3*6 = 18 feet per second. Since Evita''s rate is twice Pablo''s rate, Pablo''s rate is 1/2 Evita''s rate: (1/2)(18) = 9 feet per second. How many feet does Pablo walk in an hour? Since Pablo''s rate is 9 feet ...”
April 13, 2018
GMATGuruNY posted a reply to GMATPrep EP2: One key to predicting a competitor's in the Reading Comprehension forum
“The correct answer must be supported by EVERY PARAGRAPH. Paragraph 1: One key to predicting a competitor''s strategies is understanding how much that competitor resembles your company. Paragraph 2: In the fast-food industry, two players faced the same market trends but responded in markedly ...”
April 13, 2018
GMATGuruNY posted a reply to Each letter of a 5-letter password must be a different lette in the Problem Solving forum
“The values in red are incorrect. (21*20*19)/(1*2*3) = 1330.”
April 13, 2018
GMATGuruNY posted a reply to Each letter of a 5-letter password must be a different lette in the Problem Solving forum
“From the 5 slots in the sequence, the number of ways to choose 2 slots for the 2 vowels = 5C2 = (5*4)/(2*1) = 10. Of these 10 options, the following 4 combinations are composed of adjacent slots and thus are not allowed: Slots 1 and 2 Slots 2 and 3 Slots 3 and 4 Slots 4 and 5 Thus: Number of ...”
April 13, 2018
GMATGuruNY posted a reply to When a positive integer n is divided by 5, the remainder is in the Data Sufficiency forum
“When n is divided by 5, the remainder is 2. In other words, n is 2 MORE THAN A MULTIPLE OF 5: n = 5a + 2, where a is a nonnegative integer. Options for n: 2, 7, 12, 17, 22, 27, 32... Statement 1: n is divisible by 2 From the blue list above, even options for n: 2, 12, 22, 32... If n=2, ...”
April 13, 2018
GMATGuruNY posted a reply to 24 computer hackers can scan and infect 10 computers in in the Problem Solving forum
“Use the following equation: (workers)(time) / output = (workers)(time) / output In the equation above: Workers and time are INVERSELY PROPORTIONAL. As the number of workers increases, the amount of time required to produce the same output decreases. Workers and output are DIRECTLY ...”
April 12, 2018
GMATGuruNY posted a reply to GMATPrep EP2: One key to predicting a competitor's in the Reading Comprehension forum
“From the passage: Companies that have different assets, resources, capabilities, and positions within a market will likely also have different responses to market conditions. In the fast-food industry, for example, two players faced the same market trends, resulting from the public''s concerns ...”
April 12, 2018
GMATGuruNY posted a reply to If the elements of set X are a, b, c and d, is the average ( in the Data Sufficiency forum
“SUM = (COUNT)(AVERAGE). Statement 1: Since every pair of elements must have an average of 10, the SUM of every pair of elements = (count)(average) = 2*10 = 20. For every pair to yield a sum of 20, every value in the set must be equal to 10: 10, 10, 10, 10. If any pair of values is selected ...”
April 12, 2018
GMATGuruNY posted a reply to Which of the following is equal to x!/(x+1)! + (x+1)!/(x+2)! in the Problem Solving forum
“Let x=1. Plugging x=1 into the given expression, we get: $$\frac{1!}{\left(1+1\right)!}+\frac{\left(1+1\right)!}{\left(1+2\right)!}= {\frac{1}{2}}{ } + {\frac{1}{3}}{ } = {\frac{5}{6}}{ } $$ The target value is 5/6. Now plug x=1 into the answer choices to see which yields the target value of ...”
April 12, 2018
GMATGuruNY posted a reply to If an organization were to sell n tickets for a theater in the Problem Solving forum
“The number of tickets is irrelevant. If 5% fewer tickets are sold, then the revenue decreases by 5%. Let the cost of the production = 100. If all the tickets are sold, the revenue is 20% more than the cost of the production: 100 + (20% of 100) = 100 + 20 = 120. If 5% fewer tickets are sold, ...”
April 12, 2018
GMATGuruNY posted a reply to After increasing steadily for centuries, in the Sentence Correction forum
“Generally, COMMA + with serves to introduce something that ACCOMPANIES or FACILITATES the preceding action. B: the annual total catch...peaked in 1989, but with the total catch since then Here, the usage of COMMA + but with conveys that the portion in red accompanied the action in blue. This ...”
April 11, 2018
GMATGuruNY posted a reply to Operations with Integers in the Problem Solving forum
“Let $B = the amount spent on bananas and $A = the amount spent on apples. Since each banana sells for 50 cents, we get the following options for $B, in cents: 50, 100, 150, 200... Every value in the list above ends in 50 or 00. Implication: Since $B + $A = 630, $A must end in either 80 or ...”
April 11, 2018
GMATGuruNY posted a reply to Is x^2-y^2>x+y? in the Data Sufficiency forum
“Perfect!”
April 11, 2018
GMATGuruNY posted a reply to Reggie was hiking on a 6-mile loop trail at a rate of 2 in the Problem Solving forum
“Let Reggie travel CLOCKWISE. Since Reggie''s rate = 2 mph, the distance traveled by Reggie in 1 hour = rt = 2*1 = 2 miles. At this point, Cassie can travel clockwise to catch-up to Reggie or counterclockwise to meet him. Test the time required if Cassie travels COUNTERCLOCKWISE, with the result ...”
April 10, 2018
GMATGuruNY posted a reply to Over a three-week period, the price of an ounce of gold in the Problem Solving forum
“Let G = 100. After a 25% increase, the price = 100 + (25/100)(100) = 100 + 25 = 125. After a 20% decrease, the price = 125 - (20/100)(125) = 125 - 25 = 100. After a 5% increase, the price = 100 + (5/100)(100) = 100 + 5 = 105. The question stem asks for the final price: 105. Now plug G=100 ...”
April 10, 2018
GMATGuruNY posted a reply to Evaluate the Argument............OG Diagnostic test in the Critical Reasoning forum
“Premise: Metal rings recently excavated in Mexico were made using the same metallurgical techniques as those used by Ecuadorian artisans. Conclusion: The metallurgical techniques used to make the rings found in Mexico were learned by Mexican artisans from Ecuadorian counterparts. Rephrase the ...”
April 10, 2018
GMATGuruNY posted a reply to Is x>0? in the Data Sufficiency forum
“Statement 1: (x+y)² > (x-y)² x² + y² + 2xy > x² + y² - 2xy 2xy > -2xy 4xy > 0 xy > 0. Implication: x and y have the SAME SIGN. Since x and y could both be positive or both be negative, INSUFFICIENT. Statement 2: x+y > x-y y > -y 2y > 0 y > 0. No ...”
April 10, 2018
GMATGuruNY posted a reply to How many ways could three people sit at a table in the Problem Solving forum
“Let the 3 people be A, B and C. Number of options for A = 5. (Any of the 5 seats.) Number of options for B = 4. (Any of the 4 remaining seats.) Number of options for C = 3. (Any of the 3 remaining seats.) To combine these options, we multiply: 5*4*3 = 60. The correct answer is C.”
April 9, 2018
GMATGuruNY posted a reply to Is x^2-y^2>x+y? in the Data Sufficiency forum
“Question stem, rephrased: Is (x+y)(x-y) > x+y? Statement 1: x - y < 0 If x-y = -1 and x+y = 1, then (x+y)(x-y) = -1 and x+y = 1, so the answer to the question stem is NO. If x-y = -1 and x+y = -1, then (x+y)(x-y) = 1 and x+y = -1, so the answer to the question stem is YES. ...”
April 9, 2018
GMATGuruNY posted a reply to 700-800 Level Manhattan GMAT in the Sentence Correction forum
“COMMA + as compared is a valid construction. An OA in GMATPrep: CEO’s now earn 419 times the pay of blue-collar workers, as compared to 42 times their pay, the ratio in 1980. Proposed revision: Studies of test scores show that watching television has a markedly positive effect on ...”
April 9, 2018
GMATGuruNY posted a reply to A jar contains 4 balls, labeled 1,2,3, and 4. A ball is sel in the Problem Solving forum
“P = (ways to draw 2 balls with a difference of 1)/(total ways to draw 2 balls). Total ways to draw 2 balls: Number of options for the first ball = 4. (Any of the 4 numbers.) Number of options for the second ball = 4. (Any of the 4 numbers.) To combine these options, we multiply: 4*4 = 16. ...”
April 9, 2018
GMATGuruNY posted a reply to Is the sum of 3 positive integers divisible by 6 ? in the Data Sufficiency forum
“Here are a few ways: Only one of the three integers is odd. Exactly one of the three integers is odd. Exactly two of the three integers are even. Only the least of the three integers is odd. Of the three integers, only the greatest is odd.”
April 8, 2018
GMATGuruNY posted a reply to Is the sum of 3 positive integers divisible by 6 ? in the Data Sufficiency forum
“The interpretation in red is incorrect. Statement 1 states only that -- of the 3 positive integers -- the SMALLEST is odd. Statement 2 states only that -- of the 3 positive integers -- the GREATEST is odd. Neither statement indicates that ONLY ONE of the integers is odd.”
April 8, 2018
GMATGuruNY posted a reply to Is the sum of 3 positive integers divisible by 6 ? in the Data Sufficiency forum
“Statements combined: Case 1: The 3 integers are 1, 6, and 11, with the result that the sum of the 3 integers = 1+6+11 = 18 Since 18 is divisible by 6, the answer to the question stem is YES. Case 2: The 3 integers are 1, 5, and 11, with the result that the sum of the 3 integers = 1+5+11 = 17 ...”
April 8, 2018
GMATGuruNY posted a reply to A 45° - 45° - 90° right triangle has hypotenuse of length in the Problem Solving forum
“The sides of a 45-45-90 triangle are in the following ratio: s : s : s√2. Let s=1, implying that h = s√2 = (1)(√2) = √2. In a 45-45-90 triangle, the legs constitute the base and height. Since each leg has a length of 1, we get: Area = (1/2)bh = (1/2)(1)(1) = 1/2. The question stem ...”
April 8, 2018
GMATGuruNY posted a reply to In a certain performance of a 3-act play, the first act was in the Problem Solving forum
“Total number of minutes = (number of acts)(average number of minutes per act) = 3*46 = 138. We can PLUG IN THE ANSWERS, which represent the time for the third act. When the correct answer is plugged in, the total number of minutes = 138. B: 39 minutes Since the first act is 18 minutes shorter ...”
April 8, 2018
GMATGuruNY posted a reply to Set Problem in the Problem Solving forum
“Total who pass = Physics + Chemistry + Math - (exactly 2 subjects) - 2(all 3 subjects). Since 10 of 100 students pass none of the 3 subjects, the total number who pass at least one subject = 100-10 = 90. Of these 90 students, 80 pass Physics, 70 pass Chemistry, and 40 pass Math. Plugging these ...”
April 7, 2018
GMATGuruNY posted a reply to At a particular grade school, there are two math classes in the Data Sufficiency forum
“Statements combined: Case 1: W = 5*5 students and Z = 5*5*9*9 students Here, 5 is the only prime factor common to W and Z, and Z is a multiple of 9 In this case, the GCF of W and Z is 25. Case 2: W = 5*5*5 students, Z = 5*5*5*9*9*9 students Here, 5 is the only prime factor common to W and Z, ...”
April 7, 2018
GMATGuruNY posted a reply to A bag has 4 blue, 3 yellow and 2 green balls. The balls in the Problem Solving forum
“Number of options for the 4 blue balls = 5. (0, 1, 2, 3, or 4 blue balls may be chosen, for a total of 5 options.) Number of options for the 3 yellow balls = 4. (0, 1, 2, or 3 yellow balls may be chosen, for a total of 4 options.) Number of options for the 2 green balls = 3. (0, 1, or 2 green ...”
April 7, 2018
GMATGuruNY posted a reply to A basketball coach will select the members of a five-player in the Problem Solving forum
“Since 5 of the 9 players are included on the team, P(John is included) = 5/9. Since 4 of the remaining 8 players are included on the team, P(Peter is included) = 4/8. To combine the probabilities, we multiply: 5/9 * 4/8 = 5/18. The correct answer is D. Alternate approach: P = (5-member ...”
April 7, 2018
GMATGuruNY posted a reply to If the average (arithmetic mean) price of apples, bananas an in the Data Sufficiency forum
“Sum of the 3 prices = (number of prices)(average price) = 3*3 = $9. Statement 1: A=$3, implying that B+C = 9-3 = $6 Case 1: B=$3 and C=$3, with the result that B+C = $6 In this case, the 3 prices are as follows: $3, $3, $3 Thus, the median price = 3. Case 2: B<$3 and C>$3 or B>$3 ...”
April 7, 2018
GMATGuruNY posted a reply to In how many ways can 3 different portraits be mounted in the Problem Solving forum
“Number of options for the first portrait = 4. (Any of the 4 walls.) Number of options for the second portrait = 3. (Any of the 3 remaining walls.) Number of options for the last portrait = 2. (Either of the 2 remaining walls.) To combine the options above, we multiply: 4*3*2 = 24. The correct ...”
April 7, 2018
GMATGuruNY posted a reply to A company has two models of computers, model M and in the Problem Solving forum
“Let the task = 18 units. Since M takes 18 minutes to complete the 18-unit task, M''s rate = w/t = 18/18 = 1 unit per minute. Since N takes 9 minutes to complete the 18-unit task, N''s rate = w/t = 18/9 = 2 units per minute. Combined rate for M+N = 1+2 = 3 units per minute. For the 18-unit task ...”
April 7, 2018
GMATGuruNY posted a reply to Headway is now targeted at a wider readership - to include a in the Critical Reasoning forum
“The OA is invalid. Passage: Headway is now targeted at a wider readership -- to include all NUT members who are on the leadership salary spine. Implication: Before now, Headway did not include ALL NUT MEMBERS on the leadership salary spine. Since we know only that Headway did not include ALL ...”
April 6, 2018
GMATGuruNY posted a reply to GMATPrep: Quasars are so distant that their in the Sentence Correction forum
“The past perfect (had + VERBed) serves to express an action or state-of-being completed before another past event. B: they had been during the formation of the universe Here, the state-of-being conveyed by the past perfect verb in red is not completed before another past event. Thus, the usage of ...”
April 6, 2018
GMATGuruNY posted a reply to 5 blue marbles, 3 red marbles and 4 purple marbles in the Problem Solving forum
“P(not 2 blue and 2 purple) = 1 - P(exactly 2 blue and exactly 2 purple). P(exactly n times) = P(one way) * total possible ways. P(one way): One way to get exactly 2 blue and exactly 2 purple: BBPP. P(B on the 1st pick) = 5/12. (Of the 12 marbles, 5 are blue.) P(B on the 2nd pick) = 4/11. ...”
April 6, 2018
GMATGuruNY posted a reply to Is x > y? in the Data Sufficiency forum
“Statement 1: If x=1 and y=0, then the answer to the question stem is YES. If x=0 and y=1, then the answer to the question stem is NO. INSUFFICIENT. Statement 2: If x=1 and y=0, then the answer to the question stem is YES. If x=-1 and y=0, then the answer to the question stem is NO. ...”
April 6, 2018
GMATGuruNY posted a reply to Is M<0? in the Data Sufficiency forum
“Statement 1: It''s possible that M=0, in which case the answer to the question stem is NO. It''s possible that M=-1 in which case the answer to the question stem is YES. INSUFFICIENT. Statement 2: If M=3, then the answer to the question stem is NO. If M=-3, then the answer to the question ...”
April 6, 2018
GMATGuruNY posted a reply to In a courtyard, one bell rings every 1/4 hour and another in the Problem Solving forum
“To make the math easier, let the total timeline = the LCM of the two denominators 4 and 5 = 20 minutes. Dividing a 20-minute timeline into 5ths and 4ths, we get: 0....4...5...8...10...12...15...16...20. Each of the values above represents a ring. The timeline yields the following intervals ...”
April 6, 2018
GMATGuruNY posted a reply to Both car A and car B set out from their original locations.. in the Problem Solving forum
“Let t = A'' s time, implying that t+2 = B''s time. Since A''s rate = 65 mph, the total distance traveled by A in t hours = 65t. Since B''s rate = 50 mph, the total distance traveled by B in t+2 hours = 50(t+2). Since B travels BACK AND FORTH, while A travels only in only ONE DIRECTION, B''s total ...”
April 6, 2018
GMATGuruNY posted a reply to If 1.5/(0.2 + x) in the Problem Solving forum
“To clear the decimals, multiply the top and the bottom of the red fraction by 10: 15/(2 + 10x) = 5. Since 15/3 = 5, the expression in blue must be equal to 3: 2 + 10x = 3 10x = 1 x = 1/10. The correct answer is B.”
April 5, 2018
GMATGuruNY posted a reply to A work crew of 4 Men takes 5 days to complete one-half in the Problem Solving forum
“Let the rate for each man = 1 unit per day, implying that the combined rate for 4 men = 4 units per day. Since the rate for the original 4-men crew = 4 units per day, the amount of work produced in the first 5 days = rt = 4*5 = 20 units. Since these 20 units constitute 1/2 the job -- implying that ...”
April 5, 2018
GMATGuruNY posted a reply to Is √x+x>-√y? in the Data Sufficiency forum
“Question stem, rephrased: Is √x + √y + x > 0? Statement 1: Substituting √x+√y = 1 into the rephrased question stem, we get: 1 + x > 0 ? x > -1? Since √x implies that x≥0, the answer to the blue question is YES. SUFFICIENT. Statement 2: Substituting x = POSITIVE into ...”
April 5, 2018
GMATGuruNY posted a reply to The tornado left a path of destruction in its wake, causing in the Sentence Correction forum
“and must serve to connect PARALLEL FORMS. A: the collapse of several homes, massive power outages, tearing apart construction projects, and widespread business closures. Here, the blue portions are all composed of NOUNS and MODIFIERS, while the red portion is composed of a VERBing (tearing ...”
April 5, 2018
GMATGuruNY posted a reply to A troublesome scrub jay in the Sentence Correction forum
“to tend to do X = to be inclined to do X. A scrub jay can remember when it cached a particular piece of food in a particular place and tends not to bother to recover a perishable treat it stored long enough to have rotted. If tends is construed to be parallel with cached, we get the following: ...”
April 4, 2018
GMATGuruNY posted a reply to With the patience of its customers and.......OG2018 in the Sentence Correction forum
“B: with the patience of its customers and its network Case 1: the patience and its network are intended to be parallel, as follows: WITH THE PATIENCE and WITH ITS NETWORK. Case 2: its customers and its network are intended to be parallel, as follows: OF ITS CUSTOMERS and OF ITS NETWORK Case 2 ...”
April 4, 2018
GMATGuruNY posted a reply to OG: Metal rings recently excavated form in the Critical Reasoning forum
“Premise: Metal rings recently excavated in Mexico were made using the same metallurgical techniques as those used by Ecuadorian artisans. Conclusion: The metallurgical techniques used to make the rings found in Mexico were learned by Mexican artisans from Ecuadorian counterparts. Rephrase the ...”
April 4, 2018
GMATGuruNY posted a reply to Car A drives from P to Q at a constant rate of 100 km per ho in the Problem Solving forum
“Since A''s rate is 100 km per hour, the distance traveled by A in the first hour = 100 km. Remaining distance between A and B = (total distance) - (distance traveled by A in the first hour) = 600-100 = 500 km. When A and B drive toward each other, they WORK TOGETHER to cover the remaining 500 km ...”
April 4, 2018
GMATGuruNY posted a reply to Of the goose eggs laid at a certain pond, 2/3 hatched and... in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the total number of eggs. When the correct answer is plugged in, the number of geese that survive the first year = 120. The fractions in the prompt -- 2/3, 3/4 and 3/5 -- imply that the correct answer that the correct answer must be a multiple of 3, 4 ...”
April 4, 2018
GMATGuruNY posted a reply to The number of stamps that Kaye and Alberto had were... in the Problem Solving forum
“The answer choices imply that the values in the problem are all MULTIPLES OF 10. Since K:A = 5:3, the following options are implied: K=50, A=30 K=100, A=60 K=150, A=90 K=200, A=120. After K gives away 10 stamps and A receives 10 stamps, the resulting values for K and A must be in a ratio ...”
April 4, 2018
GMATGuruNY posted a reply to With the patience of its customers and.......OG2018 in the Sentence Correction forum
“The phrase in blue is not redundant. One definition of initiative is an action intended to solve a problem. Thus: new initiatives = new actions intended to solve a problem.”
April 3, 2018
GMATGuruNY posted a reply to Five years ago Jim was three times as old as Raoul in the Problem Solving forum
“Test the SMALLEST POSSIBLE CASE. Five years ago Jim was three times as old as Raoul was and Monica was six years older than Raoul was. Let R=1, implying that J = 3R = 3*1 = 3 and that M = R+6 = 1+6 = 7. In this case, their ages 5 years from now -- in other words, 10 years beyond 5 years ago -- ...”
April 3, 2018
GMATGuruNY posted a reply to Is |x−y|>|x+y| ? in the Data Sufficiency forum
“Is |x-y| > |x+y|? When each side of an inequality is an absolute value, we can square the inequality. (x-y)² > (x+y)² x² - 2xy + y² > x² + 2xy + y² 0 > 4xy 0 > xy. The resulting inequality is true only if x and y have different signs. Question stem, rephrased: ...”
April 3, 2018
GMATGuruNY posted a reply to If x and y are positive integer, what is the remainder in the Data Sufficiency forum
“When x is divided by y, the remainder is R. This statement implies the following: x is R more than a multiple of y. Translated into math: x = ky + R, where k is an integer such that k≥0. Statement 1: When x is divided by 2y, the remainder is 4 Case 1: y=3, implying that 2y=6 Here, when x ...”
April 2, 2018
GMATGuruNY posted a reply to Are there more girls than boys at a school? in the Data Sufficiency forum
“Statement 1: (3/7)G > (1/3)B G > (7/3)(1/3)B G > (7/9)B. Case 1: B=9 Substituting B=9 into G > (7/9)B, we get: G > (7/9)(9) G > 7. If G=8, then there are more boys than girls, so the answer to the question stem is NO. If G=10, then there are more girls than boys, so the ...”
April 2, 2018
GMATGuruNY posted a reply to What is the value of x^2 - y^2? in the Data Sufficiency forum
“Statement 1: x+y = 16 If x=8 and y=8, then x² - y² = 8² - 8² = 0. If x=10 and y=6, then x² - y² = 10² - 6² = 64. Since x² - y² can be different values, INSUFFICIENT. Statement 2: x-y = 0, implying that x=y Substituting x=y into x² - y², we get: x² - y² = x² - x² = 0. ...”
April 1, 2018
GMATGuruNY posted a reply to On his morning jog, Charles runs through a park in the in the Problem Solving forum
“rate = distance/time. Let the diameter = 7 meters, implying that the circumference of the semicircle = (πd)/2 = A.”
April 1, 2018
GMATGuruNY posted a reply to By recording the noise of crinkled wrappers as they were in the Sentence Correction forum
“A, C and E: By recording the noise of crinkled wrappers as they were slowly stretched out in an otherwise silent chamber, a team of scientists found the noise. The phrase in red distorts the intended meaning. When the crinkled wrappers were STRETCHED OUT, the noise was not found; it was CREATED. ...”
April 1, 2018
GMATGuruNY posted a reply to In a race of 6 horses A, B, C, D, E and F, what is the prob in the Problem Solving forum
“Within the race, the number of possible orderings for A, B and C = 3! = 6. Since there are 2 orderings in which A appears before both B and C -- ABC and ACB -- we get: P(A appears before both B and C) = 2/6 = 1/3. The correct answer is B.”
April 1, 2018
GMATGuruNY posted a reply to The discovery of glass being expandable and able to be shape in the Sentence Correction forum
“The wording in A indicates that the underlined portion should be extended as follows: A, B and C: The discovery of glass...revolutionized glass-working. This meaning is nonsensical. Whereas the red portion implies that glass was something NEW, the blue portion implies that glass HAD LONG ...”
March 31, 2018
GMATGuruNY posted a reply to Critical points method for inequality Is x^2 > 1/x? in the Data Sufficiency forum
“CRITICAL POINTS occur where an inequality is UNDEFINED and where the two sides are EQUAL. To determine the valid range for an inequality, test one value to the left and right of each critical point. Question stem: x² > 1/x ? Here, the critical points are x=0 (in which case 1/x is undefined) ...”
March 31, 2018
GMATGuruNY posted a reply to In many of the world’s regions, increasing pressure on wat in the Sentence Correction forum
“Generally: NO COMMA + so that serves to introduce the INTENT of the preceding clause. COMMA + so that serves to introduce the CONSEQUENCE of the preceding clause. OA: In many of the world’s regions, increasing pressure on water resources has resulted from expanding development, changes in ...”
March 30, 2018
GMATGuruNY posted a reply to A patient is given exactly 750 millimeters of a mixture of in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the amount of Medication B in the mixture. When the correct answer is plugged in, the amount of painkiller = 215. D: Medication B=425, implying that Medication A = 750-425 = 325 Amount of painkiller = (20% of B) + (40% of A) = 85 + 130 = 215. ...”
March 30, 2018
GMATGuruNY posted a reply to What is the area of the shaded region? in the Problem Solving forum
“Shaded region = (triangle area - sector area)/2 = (12 - sector area)/2 = 6 - (sector area)/2. The expression in blue implies that the correct answer must be A or B. Option A yields a negative value: 6 - 3π ≈ 6 - 9 = -3. The correct answer is B.”
March 30, 2018
GMATGuruNY posted a reply to Health insurance Plan A requires the insured to pay $1000 or in the Problem Solving forum
“Nothing is wrong with C; it is the OA. Several solutions are posted here: https://www.beatthegmat.com/health-insurance-plan-a-requires-the-insured-to-pay-1000-t301243.html”
March 29, 2018
GMATGuruNY posted a reply to Thomas Eakins' powerful style-The present perfect tense coul in the Sentence Correction forum
“Generally: to + NOUN serves to convey DIRECTION. The ball was thrown TO MARY. Conveyed meaning: The ball was thrown in Mary''s direction. for + NOUN serves to convey BENEFIT. Vegetables are good FOR CHILDREN. Conveyed meaning: Children derive BENEFIT from the consumption of vegetables. ...”
March 29, 2018
GMATGuruNY posted a reply to How many different three-digit numbers can be formed which c in the Problem Solving forum
“Integers with exactly 2 digits the same = Total integers - Integers with all 3 digits the same - Integers with all 3 digits different. Total integers: To count consecutive integers, use the following formula: Number of integers = biggest - smallest + 1. Biggest 3-digit integer = 999. Smallest ...”
March 29, 2018
GMATGuruNY posted a reply to In a rare coin collection, one in six coins is gold... in the Problem Solving forum
“Since all of the values in the problem are multiples of 10, the current number of coins is almost certainly a multiple of 10. Since 1 of every six coins is gold, G : S = 1:5, implying that the number of silver coins is 5 times the number of gold coins. Options for G and S: G=10, S=50 G=20, ...”
March 29, 2018
GMATGuruNY posted a reply to In how many ways can the letters of the word ABACUS... in the Problem Solving forum
“Since the vowels must appear together, put them together in a BLOCK: D: (4! * 3!)/2! = 4! * 3. The correct answer is D.”
March 29, 2018
GMATGuruNY posted a reply to Andrew borrows equal sums of money under simple interest... in the Problem Solving forum
“- Let x = the number of months of 5% interest, implying that x+6 = the number of months of 4% interest. Since the amount yielded in each case must be the SAME, we get: 0.05x = 0.04(x+6) 5x = 4(x+6) 5x = 4x + 24 x = 24. Thus, Andrew pays 24 months -- or 2 years -- of 5% interest, for a total ...”
March 28, 2018
GMATGuruNY posted a reply to OG Jacob Burkhardt's view that Renaissance in the Reading Comprehension forum
“Jacob Burckhardt’s view that Renaissance European women “stood on a footing of perfect equality” with Renaissance men has been repeatedly cited by feminist scholars as a prelude to their presentation of rich historical evidence of women’s inequality. A prelude is an INTRODUCTION. ...”
March 28, 2018
GMATGuruNY posted a reply to Under high pressure and intense heat, graphite in the Sentence Correction forum
“and must serve to connect PARALLEL FORMS. A, B and C: graphite changes...and remaining Here, changes (verb) and remaining (modifier) are not parallel forms. Eliminate A, B and C. Generally, in this way refers to the METHOD used to achieve a desired result. D: Under high pressure and intense ...”
March 28, 2018
GMATGuruNY posted a reply to og18: A pioneer journalist, Nellie Bly’s exploits in the Sentence Correction forum
“This SC is discussed at length here: https://www.beatthegmat.com/a-pioneer-journalist-nellie-bly-s-exploits-t278326-15.html”
March 28, 2018
GMATGuruNY posted a reply to Which of the following inequalities is equivalent to in the Problem Solving forum
“Since x=0 satisfies the given inequality, the correct answer must include 0 within its range. Eliminate A, B and D. Since x=2 satisfies the given inequality, the correct answer must include 2 within its range. Eliminate E. The correct answer is C.”
March 28, 2018
GMATGuruNY posted a reply to Is 2x+y>0? in the Data Sufficiency forum
“Both statements are satisfied by the following: Case 1: x=-1 and y=3 Case 2: x=-2 and y=3 In Case 1, 2x+y = 2(-1)+3 = 1, so the answer to the question stem is YES. In Case 2, 2x+y = 2(-2) + 3 = -1, so the answer to the question stem is NO. Since the answer is YES in Case 1 but NO in Case 2, the ...”
March 28, 2018
GMATGuruNY posted a reply to Is i>j? in the Data Sufficiency forum
“Statement 1: Case 1: k=1, j=2 and i=1, with the result that k²j=2 and ki=1 In this case, i < j, so the answer to the question stem is NO. Case 2: k=-1, j=-2 and i=3, with the result that k²j=-2 and ki=-3 In this case, i > j, so the answer to the question stem is YES. Since the answer is ...”
March 27, 2018
GMATGuruNY posted a reply to If function f(x) satisfies f(x)=f(x^2) . . . . in the Problem Solving forum
“Let the function be defined as follows: f(x) = 2. Implication: For any INPUT value, the OUTPUT value will always be 2, with the result that f(x) = f(x²) = 2. Since the output value will always be 2, the answer choices imply the following: A. f(4)=f(2)f(2) --> 2 = 2*2. B. f(16)-f(-2)=0 ...”
March 27, 2018
GMATGuruNY posted a reply to Is x < y? in the Data Sufficiency forum
“Statement 1: No information about x. INSUFFICIENT. Statement 2: No information about y. INSUFFICIENT. Statements combined: Case 1: z=0, y=2 and x=1 In this case, x < y so the answer to the question stem is YES. Case 2: z=0, y=1 and x=2 In this case, x > y, so the answer to the ...”
March 27, 2018
GMATGuruNY posted a reply to If a and b are both positive, what percent of b is a? in the Data Sufficiency forum
“Question: What FRACTION of b is a? In other words: a is what FRACTION of b? Answer: a/b. Question: What PERCENT of b is a? In other words: a is what PERCENT of b? Answer: a/b * 100. To convert the fraction in blue to a percent, we simply multiply by 100. Thus, to answer the question stem ...”
March 27, 2018
GMATGuruNY posted a reply to A code is to be made by arranging 7 letters. Three of the in the Problem Solving forum
“The clause in red seems to imply that repeated letters are IDENTICAL. Thus, the three A''s are identical and the two B''s are identical Number of ways to arrange 7 letters = 7!. But when an arrangement includes IDENTICAL elements, we must divide by the number of ways each set of identical ...”
March 27, 2018
GMATGuruNY posted a reply to If x is an integer, is x odd? in the Data Sufficiency forum
“Statement 1: 3x + 3 = odd 3x = odd - 3 3x = odd - odd 3x = EVEN. Since x must be an integer, the resulting equation in blue is true only if x is EVEN. Thus, the answer to the question stem is NO. SUFFICIENT. Statement 2: Since x² is even -- and x must be an INTEGER -- x² must be an ...”
March 27, 2018
GMATGuruNY posted a reply to If u and v are positive real numbers, is u>v? in the Data Sufficiency forum
“The question stem asks whether v < u. As shown in my solution above, v < u would require that u simultaneously be both a fraction and a value greater than 1. Since it is not possible for u to be simultaneously both a fraction and a value greater than 1, we can conclude that v is NOT less ...”
March 26, 2018
GMATGuruNY posted a reply to Sam, Mark and Joe work every day of the week, and each works in the Problem Solving forum
“Alternate approach: Mark worked twice as many hours as Sam. Joe worked three times as many hours as Mark. Let S = 1 hour. Since Mark works twice as many hours as Sam, M = 2*1 = 2 hours. Since Joe works 3 times as many hours as Mark, J = 3*2 = 6 hours. Total work-hours = 1+2+6 = 9. Of the 9 ...”
March 26, 2018
GMATGuruNY posted a reply to How many ways can the five digits 3, 3, 4, 5, 6 be arranged in the Problem Solving forum
“Good arrangements = (all possible arrangements) - (bad arrangements). All possible arrangements: Number of ways to arrange 5 digits = 5! = 120. But the five digits here include two identical 3''s. When an arrangement includes IDENTICAL elements, we must divide by the number of ways each set ...”
March 26, 2018
GMATGuruNY posted a reply to If u and v are positive real numbers, is u>v? in the Data Sufficiency forum
“Since u and v are POSITIVE, the inequalities in the statements can be simplified by multiplying each side by v. Statement 1, rephrased: u³ < v Case 1: u=1 and v=2 In this case, u < v, so the answer to the question stem is NO. Case 2: u=1/2 and v=1/3 In this case, u > v, so the ...”
March 26, 2018
GMATGuruNY posted a reply to OG12: The play La Finestrina in the Critical Reasoning forum
“The correct answer must be supported by the information in the passage. C: In the United States, the training of actors in the twentieth century is based on principles that do not differ radically from those that underlay the training of actors in eighteenth-century Italy The passage offers no ...”
March 25, 2018
GMATGuruNY posted a reply to OG12: The play La Finestrina in the Critical Reasoning forum
“Since the correct answer must be supported by the passage -- implying that the correct answer is a valid INFERENCE that can be drawn from the passage -- the problem above may be considered an inference CR.”
March 25, 2018
GMATGuruNY posted a reply to In a two-month survey of shoppers, each shopper bought one o in the Data Sufficiency forum
“Statement 1: Let the total number of shoppers in the first month = 100, implying 50 X-shoppers and 50 Y-shoppers. Since 90% of the 50 shoppers in red repurchased X in the second month, the red group in the second month yields 45 X-shoppers and 5 Y-shoppers. Since 60% of the 50 shoppers in blue ...”
March 25, 2018
GMATGuruNY posted a reply to Last year 3/5 of the members of a certain club were males. T in the Data Sufficiency forum
“Let the total number of members last year = 50, implying that the number of male members last year = (3/5)(50) = 30. Question stem, rephrased: Is (new total males)/(new total members) > 3/5? Statement 2: New total members = (6/5)(50) = 60, implying that the number of new members = 10. No ...”
March 25, 2018
GMATGuruNY posted a reply to OG18: A long-term study of some 1,000 physicians indicates in the Sentence Correction forum
“Check my posts here: https://www.beatthegmat.com/a-long-term-study-of-some-1-000-physicians-indicates-that-t288311.html”
March 23, 2018
GMATGuruNY posted a reply to In country Z, 10% of the people do not have a university... in the Problem Solving forum
“Let J = job, NJ = no job, D = diploma, ND = no diploma. To organize the data, use the following DOUBLE-MATRIX: https://thumb.ibb.co/cGxPjc/matrix_job_and_diploma_0.png 40% of the people have the job of their choice. The following matrix is yielded: ...”
March 23, 2018
GMATGuruNY posted a reply to A street vendor sells only hot dogs and hamburgers, and at.. in the Problem Solving forum
“Let x = the multiplier for the original ratio and s = the number of hot dogs sold. Original ratio of hot dogs to hamburgers = 2x/x. After s hot dogs are sold, the remaining number of hot dogs = 2x - s. Since the resulting ratio of hot dogs to hamburgers is 1 to 2, we get: (2x-s)/x = 1/2 ...”
March 23, 2018
GMATGuruNY posted a reply to Richard began driving from home on a trip averaging... in the Problem Solving forum
“Since Richard travels alone at 30 mph for 1/2 hour, the distance by which Richard gets ahead = rt = (30)(1/2) = 15 miles. Since Carla is 15 miles behind Richard -- and she must catch up to Richard in 3 hours -- she must catch up by 5 miles each hour. To catch up by 5 miles each hour, Carla must ...”
March 23, 2018
GMATGuruNY posted a reply to Last year, for every 100 million vehicles that traveled on.. in the Problem Solving forum
“3 billion = 3,000,000,000 = 3*10⁹ 100 million = 100,000,000 = 10⁸. The goal is to convert 3*10⁹ vehicles into the correct number of accidents. Since there are 96 accidents for every 10⁸ vehicles, we get: (3*10⁹ vehicles) * (96 accidents)/(10⁸ vehicles) = 3*96*10 = 2880 accidents. ...”
March 22, 2018
GMATGuruNY posted a reply to If a and b are integers and 9 < a < 21 and 19 < b & in the Problem Solving forum
“Since a must be an integer: 10 ≤ a ≤ 20. Since b must be an integer: 20 ≤ b ≤ 30. Greatest option for a/b: (greatest possible a)/(smallest possible b) = 20/20 = 1. Smallest option for a/b: (smallest possible a)/(greatest possible b) = 10/30 = 1/3. Range: (greatest a/b) - ...”
March 22, 2018
GMATGuruNY posted a reply to If the positive integer n is greater than 6, what is in the Data Sufficiency forum
“-A quick lesson on remainders: Onto the problem at hand: Statement 1: In other words, n is 2 more than a MULTIPLE OF 9: n = 9a + 2, where a is nonnegative integer. Options for n: 2, 11, 20, 29... Since n must be greater than 6: If n=11, then dividing by 6 yields a remainder of ...”
March 22, 2018
GMATGuruNY posted a reply to According to the directions on a packet of smoothie mix in the Problem Solving forum
“150 12-ounce smoothies = 150*12 total ounces. Each 3-ounce packet is combined with 12 ounces of water to form one 15-ounce smoothie. Since we must make 150*12 total ounces, and every 15 ounces requires 1 packet, we get: (150*12)/15 = 120 packets. The correct answer is A.”
March 22, 2018
GMATGuruNY posted a reply to Is a + b > c + d? in the Data Sufficiency forum
“Inequalities can be ADDED together as long as the <> in each inequality faces the same direction. Here, d < b can be rephrased as b>d, allowing us to add together a>c and b>d: a+b > c+d.”
March 22, 2018
GMATGuruNY posted a reply to In how many ways can the letters of the word SPENCER be... in the Problem Solving forum
“The posted prompt has a typo: the word SPENCE should actually written as SPENCER, as follows: Since S and P must be together and N and C must be together, consider each pair a SEPARATE BLOCK in the arrangement, yielding the following list of 5 elements: E.”
March 22, 2018
GMATGuruNY posted a reply to Last year a global disturbance of weather patterns disrupted in the Critical Reasoning forum
“Premise: Despite a disruption of weather patterns, the soybean crop increased. Conclusion: The disruption of weather patterns is responsible for an increase in the price of soybeans. The correct answer choice must explain how the disruption of weather patterns has led to an increase in the price ...”
March 22, 2018