ceilidh.erickson posted a reply to GMAT Experience - Looking for advice in the I just Beat The GMAT! forum
“Your scores have been pretty inconsistent, with both quant & verbal fluctuating a lot. Given that, a 660 result is not surprising. Inconsistency on quant almost always indicates CARELESS ERRORS or sloppy technique - sometimes you get lucky, sometimes you don''t. A lot of students brush off ...”
Yesterday
ceilidh.erickson posted a reply to 660 GMAT - What are my odds? in the The Application Process forum
“It really depends on where you''re applying, and how much you stand out against other applicants in the pool. For example, applicants from France might be underrepresented in certain pools, as opposed to applicants from other countries. I''d recommend doing free consultations with any admissions ...”
Yesterday
ceilidh.erickson posted a reply to Test day in the GMAT Strategy forum
“For anyone else with questions about test day & scores, here''s an article I wrote: https://www.manhattanprep.com/gmat/blog/scheduling-your-gmat-everything-you-need-to-know-about-booking-cancelling-reporting-etc/”
Yesterday
GMATGuruNY posted a reply to A baseball team’s season consists of playing 162 games. At in the Problem Solving forum
“The team has won 58 percent of the games it has played. 58% = 58/100 = 29/50. The fraction in blue implies that the number of wins must be a MULTIPLE OF 29: If 50 games are played, the number of wins = (29/50)(50) = 29. If 100 games are played, the number of wins = (29/50)(100) = 58. If 150 ...”
Yesterday
GMATGuruNY posted a reply to Effect of several Tsunamis in the Sentence Correction forum
“A method is a PROCEDURE for accomplishing a particular goal. Since the clause in red does not discuss a procedure, it cannot be summed up as a METHOD.”
December 11, 2018
GMATGuruNY posted a reply to Effect of several Tsunamis in the Sentence Correction forum
“The SC above is modeled -- not altogether successfully -- after SC30 in the OG12: https://www.beatthegmat.com/not-sure-about-the-answer-of-a-question-from-og12-t265701.html Rather than study the SC above, stick to the official SC.”
December 11, 2018
GMATGuruNY posted a reply to The table above shows the number of students in three clubs in the Problem Solving forum
“The values in the chart DOUBLE-COUNT any student who belongs to 2 of the 3 clubs. The totals for chess and drama -- 40 and 30 -- double-count the 10 students who belong to both chess AND drama. The totals for chess and math -- 40 and 25 -- double-count the 5 students who belong to both chess AND ...”
December 11, 2018
GMATGuruNY posted a reply to This year, a woman has a lucrative one-year position. During in the Problem Solving forum
“Let r=9, with the result that 1+r = 10. Her husband can turn each dollar she gives him into 1+r, which will be deposited in a bank account. Let the wife give the husband $1, implying that the husband turns this $1 into 1+r = $10. Thus, the amount deposited into the account = $10. The ...”
December 11, 2018
GMATGuruNY posted a reply to Line DB divides Rectangle ABCD into two equal triangles. Is in the Data Sufficiency forum
“Yes, the line will be a diagonal, but the four angles created by this diagonal will each be 45 degrees only if the rectangle is a square.”
December 10, 2018
GMATGuruNY posted a reply to What is the solution set of (1+|x|)(1+x) > 0? in the Problem Solving forum
“x=0 satisfies (1+|x|)(1+x) > 0. Since x=0 is not included in B, C, D or E, eliminate B, C, D and E. The correct answer is A.”
December 10, 2018
GMATGuruNY posted a reply to Tom drives from town A to town B, driving at a constant spee in the Problem Solving forum
“Let the distance between A and B = 120 miles. Since the 120-mile distance between A and B is twice the distance between B and C, the distance between B and C = 60 miles, implying that the total distance = 120+60 = 180 miles. Since the average speed for the 120-mile leg between A and B = 60 ...”
December 10, 2018
GMATGuruNY posted a reply to If the average (arithmetic mean) of five consecutive negativ in the Problem Solving forum
“The value of k is irrelevant. For any set of 5 consecutive integers, the difference between the greatest and least will always be 4. The correct answer is A.”
December 9, 2018
GMATGuruNY posted a reply to Three photographers, Lisa, Mike and Norm, take photos of a w in the Problem Solving forum
“The sum for Lisa and Mike is 50 less than the sum for Norm and Mike. Since Mike is common to both sums, the 50-photo difference must be yielded solely by Lisa and Norm. Implication: Lisa took 50 fewer photos than Norm. We can PLUG IN THE ANSWERS, which represent the number of photos taken ...”
December 9, 2018
GMATGuruNY posted a reply to Andrew sells vintage clothing at a flea market at which he in the Problem Solving forum
“Let h=3. Since an average of $78 is sold per hour, the total revenue for 3 hours = 3*78 = 234. Since the cost for the day is composed of $150 for the table rental and $10 per hour for the assistant, the cost for the day = 150 + 3*10 = 180. P = profit = revenue - cost = 234 - 180 = 54. The ...”
December 9, 2018
GMATGuruNY posted a reply to OG2019 -Logical flow in the Critical Reasoning forum
“It takes for granted that X implies that X is an ASSUMPTION: a statement that must be true for the conclusion to hold. Thus, when X is negated, the conclusion must be invalidated. B: It takes for granted that the volunteers with the highest levels of self-esteem had better social skills than did ...”
December 8, 2018
GMATGuruNY posted a reply to OG2019 -Logical flow in the Critical Reasoning forum
“Premise: Volunteers with the highest levels of self-esteem consistently rated themselves as having much better social skills than did the volunteers with moderate levels. Conclusion: Attaining an exceptionally high level of self-esteem greatly improves one’s social skills. The correct answer ...”
December 8, 2018
ceilidh.erickson posted a reply to If all of the telephone extensions in a certain company must in the Problem Solving forum
“Here is yet another solution: Most of the time when we''re arranging n things (people in a line, letter combinations, etc) with a diminishing pool (i.e. we can''t use the same item twice), the number of arrangements is simply n!. If we could arrange these 4 numbers into extensions without any ...”
December 7, 2018
ceilidh.erickson posted a reply to Arthmetic subsequent value Problem Solving question in the Problem Solving forum
“If each row had 2 more spaces than the previous, we could imagine this as CONSECUTIVE SUM formula: sum = (average)(# of terms) The average of a consecutive set = the average of the endpoints --> (biggest + smallest)/2 The # of terms = the difference between the biggest and the smallest, divided ...”
December 7, 2018
ceilidh.erickson posted a reply to Goronian lawmaker: Goronia's Cheese Importation Board, the a in the Critical Reasoning forum
“For more on this YES / NO test for EVALUATE questions, see: https://www.beatthegmat.com/guitar-strings-often-go-dead-become-less-respon-t304393.html#820897 https://www.beatthegmat.com/because-of-a-rare-type-of-fungus-that-killed-off-many-cacao-t304283.html#820187”
December 7, 2018
ceilidh.erickson posted a reply to Goronian lawmaker: Goronia's Cheese Importation Board, the a in the Critical Reasoning forum
“When we''re asked to EVALUATE an argument, we need to establish the conclusion of the argument and its supporting premises. We then need to determine what information is MISSING. Premises: - Goronia''s Cheese Importation Board rejects about one percent of the cheese that it inspects. - the ...”
December 7, 2018
ceilidh.erickson posted a reply to 700-800 Level Questions in the GMAT Math forum
“If you''re looking for ultra-difficult problems to practice with, I recommend checking out the Manhattan Prep Advanced Quant guide. (Forgive the plug. As yet, there''s no easy way to access OG problems by difficulty level). This book contains strategies that specifically pertain to high-level ...”
December 7, 2018
ceilidh.erickson posted a reply to Economist: On average, the emergency treatment for an elderl in the Critical Reasoning forum
“This argument style is very common on the GMAT: it compares 2 things (cost of emergency care v. cost of therapeutic program) but fails to take into account any other factors. Here are some other CR questions with similar logical flaws: ...”
December 7, 2018
ceilidh.erickson posted a reply to Economist: On average, the emergency treatment for an elderl in the Critical Reasoning forum
“To WEAKEN an argument, we must first find the logical flaws / unstated assumptions in the argument. Premises: - On average, the emergency treatment for an elderly person for injuries resulting from a fall costs $11,000. - A new therapeutic program can significantly reduce an elderly person''s ...”
December 7, 2018
ceilidh.erickson posted a reply to OG 2018 Difficulty level for questions? in the GMAT Math forum
“GMAC has not published difficulty levels for any of the OGs up to OG 2018. Prep companies can only take our best guesses at the difficulty levels, based on the performances of our students. Manhattan Prep has a tool called Navigator that allows students to record their answers to every OG ...”
December 7, 2018
GMATGuruNY posted a reply to 2k years ago Frank was 3k years old. In k years Frank's age, in the Problem Solving forum
“Let k=10. 2k years ago Frank was 3k years old. Since k=10, 20 years ago Frank was 30 years old, implying that his age now = 30+20 = 50. In k years Frank''s age, in years, will be: Since Frank is now 50 years old, Frank''s age in 10 years = 50+10 = 60. The correct answer must yield a value ...”
December 7, 2018
GMATGuruNY posted a reply to Which of the following equations is satisfied by x=1+√2? in the Problem Solving forum
“Alternate approach: For any quadratic in the form x² + bx + c = 0, where b and c are rational numbers: If one of the roots is m+√n, then the other root is m-√n. Sum of the roots = -b Product of the roots = c Here, since one of the roots is 1+√2, the other root is 1-√2. Thus: -b ...”
December 7, 2018
GMATGuruNY posted a reply to Each day at Dan’s new job, he earns $10 more than the day in the Data Sufficiency forum
“Since each payday is $10 more than the preceding payday, the list of 15 paydays constitutes an EVENLY SPACED SET. Statement 1: For any evenly spaced set: Median = Sum/Quantity. Thus: Pay on the 14th day = median of the 3 most recent days = sum/quantity = 690/3 = 330. Since the pay on the ...”
December 6, 2018
GMATGuruNY posted a reply to Tom saved $10,000 at a constant compound interest rate of r in the Problem Solving forum
“Original deposit: 10,000. The balance doubles every 10 years. After 10 years, we get: 2*10,000 = 20,000. After 20 years, we get: 2*20,000 = 40,000. After 30 years, we get: 2*40,000 = 80,000. The correct answer is E.”
December 6, 2018
GMATGuruNY posted a reply to If a, b, and c are positive integers such that a < b < in the Data Sufficiency forum
“Does (a/100) * (b/100) * c = integer? Test integer values such that a < b < c. Statement 1: b = (a/100)¯¹ Thus, b = 100/a. Test the smallest possible value for a. Case 1: a=1 Here, b =100/1 = 100. In this case, (a/100) * (b/100) * c = 1/100 * 100/100 * c = c/100. If c ...”
December 5, 2018
GMATGuruNY posted a reply to If a, b, and c are positive integers, what is the remainder in the Data Sufficiency forum
“Statement 1: No information about b. INSUFFICIENT. Statement 2: No information about a. INSUFFICIENT. Statements combined: Case 1: c=3, with the result that a=3³=27 and that b=(3-2)³=1 In this case, a-b = 27-1 = 26. Dividing 26 by 6, we get: 26/6 = 4 R2 Case 2: c=4, with the ...”
December 5, 2018
GMATGuruNY posted a reply to If w, x, and y are consecutive odd positive integers and w & in the Problem Solving forum
“Test easy cases: 5-3-1 = 1 7-5-3 = -1 The case in green indicates that -1 is a possible value of y-x-w. The correct answer is C.”
December 5, 2018
GMATGuruNY posted a reply to x is a positive number. What is the median of x, √x and x^ in the Data Sufficiency forum
“To determine the median of x, √x and x², we need to know the value of x. Statement 1: Since x is positive, we can safely divide both sides by x: x²/x = x/x x = 1 SUFFICIENT. Statement 2: x² + x + 1 = 3x x² - 2x + 1 = 0 (x-1)² = 0 x = 1 SUFFICIENT. The correct answer is D.”
December 5, 2018
GMATGuruNY posted a reply to A triangle is formed by connecting three randomly chosen ver in the Problem Solving forum
“Let the 6 vertices = A, B, C, D, E and F. P(the triangle includes AT LEAST 1 side of the hexagon) = 1 - P(the triangle includes NO sides of the hexagon). From the 6 vertices, the number of ways to choose 3 to form a triangle = 6C3 = (6*5*4)/(3*2*1) = 20. Of these 20 triangles, only 2 include ...”
December 5, 2018
GMATGuruNY posted a reply to Working together, Machine A and Machine B can produce a in the Data Sufficiency forum
“Since A+B take 4 hours to produce 200 widgets, the combined rate for A+B = w/t = 200/4 = 50 widgets per hour. To determine A''s time to produce 200 widgets, we need to know A''s rate. Question stem, rephrased: What is A''s rate? Statement 1: Since B takes 5 hours to produce 50 widgets, B''s ...”
December 4, 2018
GMATGuruNY posted a reply to How many positive two-digit integers have a remainder of 1 w in the Problem Solving forum
“A quick lesson on remainders: Onto the problem at hand: a remainder of 1 when divided by 2 x = 2a + 1 = 1, 3, 5, 7... In other words, x must be ODD. a remainder of 4 when divided by 5 x = 5b + 4 = 4, 9, 14, 19... Since x must be odd, we get: x = 9, 19, 29.... a remainder of ...”
December 4, 2018
GMATGuruNY posted a reply to If there are 4 pairs of twins, and a committee will be in the Problem Solving forum
“Number of options for the 1st person = 8. Number of options for the 2nd person = 6. (Of the 7 people left, we can''t use the twin of the 1st person chosen, leaving 7-1= 6 choices.) Number of options for the 3rd person = 4. (Of the 6 people left, we can''t use the twins of the 2 people already ...”
December 3, 2018
ceilidh.erickson posted a reply to Most of Western music since the Renaissance has been based in the Critical Reasoning forum
“For more on using this strategy for BOLDFACE questions on CR, see: https://www.beatthegmat.com/gmat-official-guide-2019-in-countries-where-automobile-t303686.html#818265 https://www.beatthegmat.com/gmat-official-guide-2019-boreal-owls-range-over-a-much-t303663.html#818059 ...”
December 2, 2018
ceilidh.erickson posted a reply to Most of Western music since the Renaissance has been based in the Critical Reasoning forum
“The goal in any BOLDFACE question is to deconstruct the argument, and determine the role of each statement: - author''s conclusion / position - support for the author - the counterpoint / what others believe - support for the counterpoint - neutral / background information / establishing ...”
December 2, 2018
ceilidh.erickson posted a reply to 3 Month Study Plan? in the GMAT Strategy forum
“You have more than enough material to study! Here''s what you need to do: Here''s what you should do: 1. Take an adaptive Practice Exam (CAT). If you bought the Mprep books, you''ll have access to our entire suite of practice exams. Don''t prep first - just dive in and take the test, ...”
December 2, 2018
ceilidh.erickson posted a reply to Help me Beat the GMAT in the I just Beat The GMAT! forum
“You can''t find what went wrong? You just told us what went wrong - you over-studied! Being well-rested is absolutely critical for brain functioning (see the studies that say that being sleep-deprived made people perform worse on driving tests than being drunk). There''s nothing that you could ...”
December 2, 2018
ceilidh.erickson posted a reply to A certain bookstore, each notepad costs x dollars and each in the Data Sufficiency forum
“Translate the given information: $10 is enough to buy 5 notepads and 3 markers --> $$5x+3y\le10$$ Translate the question: is $10 enough to buy 4 notepads and 4 markers instead? --> $$4x+4y\le10\ ?$$ Simplify: $$2x+2y\le5\ ?$$ 1) Each notepad cost less than $1. If x < 1, ...”
December 2, 2018
ceilidh.erickson posted a reply to Several friends in a dinner group decide to contribute in the Data Sufficiency forum
“For similar variations on this type of word problem, see: https://www.beatthegmat.com/impossible-question-ps-203-t281881.html#739205 https://www.beatthegmat.com/dollars-t273184.html#707179 ...”
December 2, 2018
ceilidh.erickson posted a reply to Several friends in a dinner group decide to contribute in the Data Sufficiency forum
“Here, we have a version of a rate problem: ($ contribution per person)(# of people) = total $ amount contributed From the question stem, we''re given that the total amount contributed is $36. Let: c = $ contribution per person n = number of people (c)(n) = 36 Since the question is asking ...”
December 1, 2018
ceilidh.erickson posted a reply to the minimum number of straight lines required to in the GMAT Math forum
“This is not a GMAT-style question. The GMAT does not ask for this style of time-consuming puzzle problem. Please still to questions only from GMAC or reputable test prep companies.”
December 1, 2018
GMATGuruNY posted a reply to For each of her sales, a saleswoman receives a commission in the Problem Solving forum
“The first $500 of the $800 sale earns 20% commission, while the remaining $300 earns 30%. Average commission percentage per $800 = (500*20 + 300*30)/800 = (5*20 + 3*30)/8 = 190/8 = 23.75 ≈ 24. The correct answer is B.”
December 1, 2018
GMATGuruNY posted a reply to When a certain tree was first planted, it was 4 feet tall in the Problem Solving forum
“Let x = the yearly increase. Height after 4 years = 4 + 4x. Height after 6 years = 4 + 6x. At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. The phrase in red implies the following: The height in the 6th year was 6/5 of the height in the 4th ...”
December 1, 2018
GMATGuruNY posted a reply to If k is a positive integer and n=(k-1)k(k+1), is n a multipl in the Data Sufficiency forum
“Every other even integer is a MULTIPLE OF 4: 2, 4, 6, 8, 10, 12... Thus, the product of two consecutive even integers = product of a multiple of 4 and an even non-multiple of 4 = MULTIPLE OF 8: 2*4 = 8 4*6 = 2*2*2*3 = 8*3 10*12 = 2*5*2*2*3 = 8*15 Statement 1: Since k is odd, k-1 and k+1 ...”
November 30, 2018
GMATGuruNY posted a reply to If x^2=x+1, then x^4=? in the Problem Solving forum
“Squaring both sides, we get: (x²)² + (x+1)² x⁴ = x² + 2x + 1 Substituting x²=x+1 into x⁴ = x² + 2x + 1, we get: x⁴ = (x+1) + 2x + 1 x⁴ = 3x + 2 The correct answer is A.”
November 30, 2018
GMATGuruNY posted a reply to Is the positive integer p a multiple of 50? in the Data Sufficiency forum
“Any integer that is a multiple 10 is also a multiple of 5. Implication: Any integer that satisfies Statement 1 will also satisfy Statement 2. Both statements are satisfied by the following cases: Case 1: p=10, which is a multiple of 10 (and thus is also a multiple of 5) In this case, p is NOT a ...”
November 30, 2018
GMATGuruNY posted a reply to The point A, B, C, and D are on the number line, not in the Data Sufficiency forum
“The drawings below satisfy both statements: http://s4.postimage.org/1yjxdhskk/ABCD_number_line.jpg Since in the first case BD=1 and in the second case BD=17, the two statements combined are insufficient. The correct answer is E.”
November 30, 2018
GMATGuruNY posted a reply to In a business school case competition, the top three teams in the Problem Solving forum
“Case 1: Team A wins a prize, with the result that Team B must win a prize Number of prizes that could be won by A = 3. Number of remaining prizes that could be won by B = 2. Number of teams that could win the third prize = 4. (Any of the 4 remaining teams.) To combine these options, we ...”
November 30, 2018
GMATGuruNY posted a reply to The juice stall at the circus stocked just 2 brands of in the Problem Solving forum
“Let n=50, implying that 50% of the sold juice packs are A, while the other half are B. In other words, the store sells an EQUAL NUMBER of each type of juice pack. Let the store sell 2 OF EACH TYPE of juice pack. Revenue from two $1 packs of A = 2*1 = 2. Revenue from two $1.5 packs of B = ...”
November 29, 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 ...”
November 29, 2018
GMATGuruNY posted a reply to The equation of a circle in the x-y coordinate plane is x^2 in the Problem Solving forum
“The equation for a circle with its center at the origin and a radius of r is as follows: x² + y² = r². Thus, x² + y² = 25 is a circle with its center at the origin and a radius of 5. A point on this circle will have integer coordinates in three cases: Case 1: The radius is horizontal ...”
November 29, 2018
GMATGuruNY posted a reply to On a partly cloudy day, Derek decides to walk back from work in the Problem Solving forum
“The average speed -- 2.8 miles per hour -- must be BETWEEN the two individual rates (s and s+1). Thus, s = 2 miles per hour and s+1 = 3 miles per hour. We can PLUG IN THE ANSWERS, which represent the fraction traveled at 2 miles per hour. When the correct fraction is plugged in, the average ...”
November 28, 2018
GMATGuruNY posted a reply to Eight consecutive integers are selected from the integers 1 in the Data Sufficiency forum
“When consecutive positive integers are divided by positive integer x, the resulting remainders also are consecutive: If x=4: 16/4 = 4 R0. 17/4 = 4 R1. 18/4 = 4 R2. 19/4 = 4 R3. 20/4 = 5 R0. From here, the cycle of remainders will repeat: 0,1,2,3,0,1,2,3... The smallest remainder is 0. The ...”
November 28, 2018
GMATGuruNY posted a reply to A club has 10 members. One president and two vice-presidents in the Problem Solving forum
“Number of options for president = 10. (Any of the 10 members.) From the remaining 9 members, the number of ways to choose 2 to serve as vice-president = 9C2 = (9*8)/(2*1) = 36. To combine these options, we multiply: 10*36 = 360. The correct answer is E.”
November 28, 2018
GMATGuruNY posted a reply to Twelve identical machines, running continuously at the same in the Problem Solving forum
“One approach is to use the following equation: (machines)(time) / output = (machines)(time) / output In the equation above: Machines and time are INVERSELY PROPORTIONAL. As the number of machines increases, the amount of time required to produce the same output decreases. Machines and ...”
November 24, 2018
GMATGuruNY posted a reply to In a plane, there are two parallel lines. One line has 5 in the Problem Solving forum
“One approach: Good Cases = Total Cases - Bad Cases. Total Cases: From 9 points, the number of ways to choose 3 = 9C3 = (9*8*7)/(3*2*1) = 84. Bad Case 1: Choosing 3 collinear points from the 5-point line, with the result that a triangle cannot be formed From the 5 points on this line, the ...”
November 24, 2018
GMATGuruNY posted a reply to Find x^4 + 1/x^4 if x – 1/x = 2. in the Problem Solving forum
“(x – 1/x)² = 2² x² + 1/x² - 2(x)(1/x) = 4 x² + 1/x² - 2 = 4 x² + 1/x² = 6 (x² + 1/x²)² = 6² x⁴ + 1/x⁴ + (2)(x²)(1/x²) = 36 x⁴ + 1/x⁴ + 2 = 36 x⁴ + 1/x⁴ = 34. The correct answer is D.”
November 23, 2018
GMATGuruNY posted a reply to If n is an integer greater than 1, what is the value of n? in the Data Sufficiency forum
“Since the prompt indicates that n is an integer greater than 1, the case in red is not possible. The only value that satisfies Statement 2 is n=2, making Statement 2 SUFFICIENT. The correct answer thus is not C but B.”
November 23, 2018
GMATGuruNY posted a reply to What is the sum of the prime factors of 2^8-1? in the Problem Solving forum
“Alternate approach: 2⁸ - 1 = 256 - 1 = 255 = 5*51 = 5*3*17. Sum of the prime factors = 5+3+17 = 25. The correct answer is E.”
November 22, 2018
GMATGuruNY posted a reply to June 25, 1982, fell on a Friday. On which day of the week in the Problem Solving forum
“Between 1982 and 1987 are 4 non-leap years and 1 leap year. Each non-leap year is composed of 365 days; a leap year is composed of 366 days. Thus, from June 25, 1982 to June 25, 1987, the total number of days = 4(365) + 366. Since June 25, 1982 is a Friday, every passing of 7 days will yield ...”
November 22, 2018
GMATGuruNY posted a reply to A man walking at a constant rate of 4 miles per hour is pass in the Problem Solving forum
“(man''s rate)/(woman''s rate) = (4 mph)/(20 mph) = 1/5. Between the moment when the woman passes the man and the moment when she stops to wait, the woman and the man each travel for 5 minutes. During these 5 minutes, the woman travels x miles. Since the man''s rate is 1/5 the woman''s rate, the ...”
November 21, 2018
GMATGuruNY posted a reply to Six countries in a certain region sent a total of 75 in the Data Sufficiency forum
“Let the 6 countries be A, B, C, D, E and F. The question stem asks whether A≥10. Plug in A=10 (which satisfies statement 2 and is at least 10) and A=9 (which also satisfies statement 2 but is NOT at least 10). To save time, let F=41, which satisfies statement 1. Case 1: Total = 75, ...”
November 21, 2018
GMATGuruNY posted a reply to If n is an integer greater than 1, what is the value of n? in the Data Sufficiency forum
“Statement 1: Here, n can be any prime number. INSUFFICIENT. Statement 2: (n+2)/n = n/n + 2/n = 1 + 2/n. Given that n must be an integer, 1 + 2/n will yield an integer value only if n is a FACTOR OF 2. Factors of 2: 1 and 2. Since n must be greater than 1, n=2. SUFFICIENT. The correct ...”
November 21, 2018
GMATGuruNY posted a reply to A number when divided by 4 and 5 leaves remainders 1 and 4 in the Problem Solving forum
“Please fix the prompt, which has been transcribed incorrectly. It should include the word in red:”
November 20, 2018
GMATGuruNY posted a reply to A woman has seven cookies - four chocolate chip and three in the Problem Solving forum
“Alternate approach: Case 1: Deborah and Kim each receive an oatmeal cookie In this case, 4 chocolate chip cookies and 1 oatmeal cookie remain. The remaining oatmeal cookie has 5 options: Nicole, Ronit, Mark, Terrance, or no one. Total ways = 5. Case 2: Deborah and Kim each receive a ...”
November 20, 2018
GMATGuruNY posted a reply to The Lewiston Road Race is how many kilometers long? in the Data Sufficiency forum
“Statement 1: Rate and time have a RECIPROCAL relationship. A rate ratio of (40kph) : (50kph) = 4:5 implies a time ratio of 5:4 = 10:8. The time ratio in blue implies that -- for the time at 40kph to be 2 hours more than the time at 50kph -- the time at 40kph must be 10 hours, while the time at ...”
November 17, 2018
GMATGuruNY posted a reply to Tim and Glenn are running laps around a circular track. in the Data Sufficiency forum
“Statement 1: The TIME RATIO for Tim and Glenn = 48:60 = 4:5. Since time and rate have a RECIPROCAL relationship, the RATE RATIO for Tim and Glenn = 5:4. Implication: For every 5 laps that Tim runs, Glenn runs only 4 laps. Thus, after running 5 laps, Tim will have run 1 more lap than Glenn. ...”
November 16, 2018
GMATGuruNY posted a reply to At the Trenchard Oaks apartment complex, a two-bedroom in the Problem Solving forum
“Let the one-bedroom rent = $2 per month, implying that the two-bedroom rent = 2 + (50% of 2) = 2 + 1 = $3 per month. Since the rent for a one-bedroom apartment = $2 per month, the total amount to rent a one-bedroom apartment for 12 months = 2*12 = $24. For $24, the number of months yielded for a ...”
November 16, 2018
GMATGuruNY posted a reply to A certain store will order 25 crates of apples. The apples in the Problem Solving forum
“Let W = Winesap crates, M = McIntosh crates, and R = Roma crates. Since a total of 25 crates are ordered, we get: W + M + R = 25. To MINIMIZE the value of W, we must MAXIMIZE the values of M and R. Since the store is to order more crates of Winesap than crates of McIntosh and more crates of ...”
November 15, 2018
GMATGuruNY posted a reply to A marzipan factory has two machines producing marzipan. in the Data Sufficiency forum
“The prompt states: Every day, the two machines operate constantly from 08:00 to 18:00. As shown in my post above, Statement 2 yields the following rate ratio: (W alone) : (W and D together) = 1:5. The rate ratio indicates that -- of every 5 kg produced when W and D work together from 8:00 to ...”
November 15, 2018
GMATGuruNY posted a reply to Organized in 1966 by the Fish and Wildlife in the Sentence Correction forum
“Generally, for + VERBing is an ADJECTIVE serving to modify a NOUN. A: The Breeding Bird Survey uses annual roadside counts along established routes for monitoring. Here, for monitoring seems to be an ADJECTIVE modifying routes, implying that the ROUTES were designed FOR MONITORING. Not the ...”
November 15, 2018
GMATGuruNY posted a reply to A marzipan factory has two machines producing marzipan. in the Data Sufficiency forum
“Statement 1: Let N = 50 kg. Since W and D produce the entire 50 kg over the 10 hours between 8:00 and 18:00, the combined rate for W and D = 50/10 = 5 kg per hour. Since W takes 25 hours to produce N/2 = 25 kg, W''s rate alone = w/t = 25/25 = 1 kg per hour. Of every 5 kg produced each hour ...”
November 14, 2018
GMATGuruNY posted a reply to If x and y are unknown positive integers, is the mean of the in the Data Sufficiency forum
“Known values, in ascending order: 1, 5, 6, 7 Statement 1: x+y = 7 Mean = sum/quantity = (1+5+6+7+x+y)/6 = (1+5+6+7+7)/6 = 26/6 = 13/3 = 4.33. Text EXTREMES. Case 1: x and y are far from each other If x=1 and y=6, we get: 1, 1. 5, 6, 6, 7 Median = (5+6)/2 = 11/2 = 5.5 Case 2: x and y ...”
November 14, 2018
GMATGuruNY posted a reply to How many positive two-digit numbers yield a remainder of 1 in the Problem Solving forum
“Let x = the two-digit number. Since dividing by 4 leaves a remainder of 1, x is equal to one more than a multiple of 4: x = 4k + 1 Since dividing by 14 leaves a remainder of 1, x is equal to one more than a multiple of 14: x = 14m + 1 Since the two expressions in blue must be equal, we ...”
November 14, 2018
ceilidh.erickson posted a reply to What is the area of the quadrilateral with vertices A, B, C, in the Data Sufficiency forum
“Fabio beat me to the post while I was still drawing diagrams <i class="em em-wink"></i> But mine will take you through both statements individually, in case anyone couldn''t rule them out as insufficient.”
November 13, 2018
ceilidh.erickson posted a reply to What is the area of the quadrilateral with vertices A, B, C, in the Data Sufficiency forum
“On a DS geometry question with no diagram given, try to draw different versions of a diagram based on the information given. Question: What is the area of the quadrilateral with vertices A, B, C, and D? We have no information about the quadrilateral to begin with. We will at least need some ...”
November 13, 2018
ceilidh.erickson posted a reply to Of patients over 65 years old who survived coronary bypass in the Critical Reasoning forum
“Whenever we''re asked to WEAKEN an argument, we must find the LOGICAL FLAW that exists between the premises and the conclusion. Premise: Of patients over 65 years old who survived coronary bypass surgery... only 75 percent benefited from the surgery Conclusion: Thus it appears that for one ...”
November 13, 2018
ceilidh.erickson posted a reply to Which of the following most logically completes the passage? in the Critical Reasoning forum
“This question is a variant of one from the Official Guide that asked about boldface portions: https://www.beatthegmat.com/scientists-go-their-work-mostly-before-the-age-of-40-t149219.html#538772”
November 13, 2018
ceilidh.erickson posted a reply to Which of the following most logically completes the passage? in the Critical Reasoning forum
“We want to support the explanation that being in a field for too long diminishes creativity, NOT that being too old in general diminishes creativity. We need a piece of information that connects to length of time in the field. (A) the average age of recipients of scientific research grants is ...”
November 13, 2018
ceilidh.erickson posted a reply to For each country listed in the left column of the table, the in the Problem Solving forum
“Let''s say that A = 1 unit of country A''s currency, X = 1 unit of country X''s currency, and so on. Using the table given, we can create equations: A = 2.2X B = 0.5X C = 0.1X D = 4.0X E = 1.7X Now, plug these into the answer choices: A. 4 units of Country A currency --> 4(2.2X) = ...”
November 13, 2018
ceilidh.erickson posted a reply to Invisible Constraint. OG # 8 vs OG#123 in the Data Sufficiency forum
“Your question is a very understandable one. If you want to be absolutely sure whether there is only one pair of values that work or multiple pairs of values, you should create a table / chart. Start by charting the maximum amount of the variable with the higher coefficient, and see if there''s a ...”
November 13, 2018
ceilidh.erickson posted a reply to If a certain company purchased computers at $2000 each and in the Data Sufficiency forum
“We have 2 unknowns in this question. Let: C = number of computers P = number of printers We''re given information about the cost of each device, but no information about the total cost, or the total number of devices. To solve for C, we''ll need either 2 equations for the 2 variables, or ...”
November 13, 2018
GMATGuruNY posted a reply to On a wedding catering service, An experienced chef can in the Problem Solving forum
“Let service = 24 units. Rate for each experienced chef = w/t = 24/8 = 3 units per hour. Rate for each novice chef = w/t = 24/12 = 2 units per hour. Combined rate for 1 experienced chef and 1 novice chef working together = 3+2 = 5 units per hour. To produce 24 units in 1.6 hours, rate = w/t = ...”
November 13, 2018
GMATGuruNY posted a reply to Jake and Ryan worked together on a job for which they were in the Problem Solving forum
“Let the hourly wage = $1 per hour. Let Ryan''s time = 10 hours, implying that Jake''s time = 10 + (20% of 10) = 10 + 2 = 12 hours. Thus: Total number of work hours = 10+12 = 22 hours. Total pay = (hourly wage)(total number of work hours) = 1*22 = $22. Since the total pay = 10+12 = $22, and ...”
November 13, 2018
GMATGuruNY posted a reply to A store purchased 20 coats that each cost an equal amount in the Data Sufficiency forum
“Statement 1: If the selling price per coat had been twice as much , the store’s gross profit on the 20 coats would have been $2,400 When the selling price per coat is doubled, the resulting profit per coat = (total profit)/(number of coats) = 2400/20 = 120. Case 1: Double the selling price = ...”
November 13, 2018
GMATGuruNY posted a reply to If 60! is written out as an integer, with how many in the Problem Solving forum
“60! = 60*59*58*....*3*2*1. Since 10=2*5, EVERY COMBINATION OF 2*5 contained within the prime-factorization of 60! will yield a 0 at the end of the integer representation of 60!. The prime-factorization of 60! is composed of FAR MORE 2''S than 5''s. Thus, the number of 0''s depends on the ...”
November 13, 2018
GMATGuruNY posted a reply to In the figure AB and CD are two diameters of circle. in the Problem Solving forum
“An INSCRIBED ANGLE is formed by two chords. A CENTRAL ANGLE is formed by two radii. When an inscribed angle and a central angle intercept the same two points on a circle, the inscribed angle is 1/2 the central angle. https://i.postimg.cc/qgbxWKdW/Angle-CEB-1.png Here, inscribed angle CFB and ...”
November 12, 2018
GMATGuruNY posted a reply to If x and y are positive integers such that x = 8y + 12, what in the Data Sufficiency forum
“Statement 1: x=12u, where u is an integer and x=8y+12. In other words, x is a multiple of 12. For x to be a multiple of 12, 8y must be a multiple of 12. If y=3, then x = 8*3 + 12 = 36. The GCD of 3 and 36 is 3. If y=6, then x = 8*6 + 12 = 60. The GCD of 6 and 60 is 6. Since the ...”
November 11, 2018
GMATGuruNY posted a reply to Eight women and two men are available to serve on a in the Problem Solving forum
“P(at least 1 man) = 1 - P(no men). P(no men): P(1st person selected is a woman) = 8/10. (Of the 10 people, 8 are women.) P(2nd person selected is a woman) = 7/9. (Of the 9 remaining people, 7 are women.) P(3rd person selected is a woman) = 6/8. (Of the 8 remaining people, 6 are women.) To ...”
November 11, 2018
GMATGuruNY posted a reply to A gardener is going to plant 2 red rosebushes and 2 white in the Problem Solving forum
“Moving LEFT TO RIGHT along the row: P(1st rosebush is white) = 2/4. (Of the 4 rosebushes, 2 are white.) P(2nd rosebush is red) = 2/3. (Of the 3 remaining rosebushes, 2 are red.) P(3rd rosebush is red) = 1/2. (Of the 2 remaining rosebushes, 1 is red.) P(4th rosebush is white) = 1/1. (The one ...”
November 10, 2018
GMATGuruNY posted a reply to Every day at noon, a bus leaves for Townville and travels at in the Problem Solving forum
“Time and rate have a RECIPROCAL RELATIONSHIP: 2 times as fast implies 1/2 the time. 3 times as fast implies 1/3 the time. Let t = the normal time. Since the bus travels today at 7/6 its normal rate, the time today is equal to 6/7 of the normal time: (6/7)t. Since the bus leaves 1/2 hour late ...”
November 9, 2018
ceilidh.erickson posted a reply to GMAT OG 2019 One proposal for preserving rain in the Reading Comprehension forum
“With EXCEPT questions, we must find proof in the passage to eliminate 4 of the 5 answer choices. A. adopt new agricultural technologies line 2: "promote the adoption of new agricultural technologies" B. grow improved plant varieties line 3: "such as improved plant ...”
November 7, 2018
ceilidh.erickson posted a reply to GMAT OG 2019 One proposal for preserving rain in the Reading Comprehension forum
“Here is what we''re told about land tenure: In other words, it''s a fact that kinship ties are more important indicator of land-tenure security than are legal property ties. Indicators aren''t necessarily always causal, but the researchers are clearly assuming that they are. And if this is ...”
November 7, 2018
ceilidh.erickson posted a reply to 12 year out of college, GMAT study plans? in the GMAT Strategy forum
“I''m sorry to hear that it didn''t go as well as you''d hoped. I want to address a few things you said: 1. Inconsistency. Your scores on both quant & verbal have bounced around a lot. Inconsistency in score usually indicates inconsistency in your process: you don''t really have a clear ...”
November 7, 2018
ceilidh.erickson posted a reply to Although they are crucially important, a person's total in the Sentence Correction forum
“This question is testing PRONOUNS, If a sentence begins with an opening modifier or dependent clause containing a pronoun (e.g. "Although they are..."), that pronoun must be referring to the SUBJECT of the main clause that comes after. So in the case of "Although they are..." ...”
November 7, 2018
ceilidh.erickson posted a reply to In California today, Hispanics under the age of eighteen in the Sentence Correction forum
“This question is primarily testing LOGICAL MEANING. Whenever language about percentages or proportions appears on SC or CR, we want to ask ourselves: "what is this the percent *of*? Is it logical and unambiguous?" (A) In California today, Hispanics under the age of eighteen account for ...”
November 7, 2018
GMATGuruNY posted a reply to There are 27 different three-digit integers that can be in the Problem Solving forum
“Given any set that is symmetrical about the median: Sum = (quantity)(median) The set of 3-digit integers that can be formed from the digits 1,2 and 3 is symmetrical about the median (222): ...212, 213, 221, 222, 223, 231, 232... Thus: Sum of the 27 integers = (quantity)(median) = 27*222 = ...”
November 7, 2018
GMATGuruNY posted a reply to Is x^2>xy? in the Data Sufficiency forum
“For the purposes of a Y/N DS problem, the rephrase is the equivalent of the original question stem. Original question stem: Is x² > xy? The answer will be YES if y/x is less than 1.. The answer will be NO if y/x is NOT less than 1. Thus, the original question stem can be rephrased as ...”
November 5, 2018
GMATGuruNY posted a reply to Is x^2>xy? in the Data Sufficiency forum
“x² > xy is true only if x is NONZERO, in which case we can safely divide by x², since the square of a nonzero value must be positive: x²/x² > (xy)/x² 1 > y/x Question stem, rephrased: Is y/x < 1? Statement 1: x > y If x=2 and y=1, then y/x =1/2. so the answer to the ...”
November 5, 2018
GMATGuruNY posted a reply to | 1 - | 2 - | 3 - | 4 – π | | | | in the Problem Solving forum
“Let π=3 in the original expression and simplify the blue portion below: | 1 - | 2 - | 3 - | 4 – 3 | | | | Simplify the red portion below; | 1 - | 2 - | 3 - 1 | | | Simplify the green portion below: | 1 - | 2 - 2 | | = | 1 - 0 | = 1 The correct answer choice must yield a value of ...”
November 5, 2018
GMATGuruNY posted a reply to Working alone, three persons P, Q, and R can do a certain in the Problem Solving forum
“Let the job = the LCM of the 3 times = 60 widgets. Maximum time: The maximum time is yielded when the slowest person -- R -- works alone. Since R takes 15 hours to complete the 60-widget job, the maximum time = 15 hours. Minimum time: The minimum time is yielded when all 3 people work ...”
November 4, 2018
GMATGuruNY posted a reply to Triplets Adam, Bruce, and Charlie enter a triathlon. If ther in the Problem Solving forum
“One approach: P(good outcome) = 1 - P(bad outcome). Bad outcome #1: Exactly 1 triplet wins. P(triplet wins 1st place) = 3/9. (Of the 9 competitors, 3 are triplets) P(non-triplet wins 2nd place) = 6/8. (Of the 8 remaining competitors, 6 are non-triplets) P(non-triplet wins 3rd place) = 5/7. ...”
November 4, 2018
ceilidh.erickson posted a reply to GMAT Retake?? in the I just Beat The GMAT! forum
“Here is a post that sums up my advice about whether to retake the exam: https://www.beatthegmat.com/my-advice-to-a-student-w-a-740-wondering-whether-to-retake-t301310.html#810959 You''re only 1 point away from perfect on the quant. To get a 720+, you would have to improve your verbal score. If ...”
November 2, 2018
ceilidh.erickson posted a reply to The difference in average annual income in (OG18) help in the GMAT Verbal & Essays forum
“This type of logical flaw is very common on GMAT CR. I like to call it "Mixed Metrics" - conflating one mathematical concept (difference in incomes increased) with another (actual incomes increased). Any time you see one statistic / metric / mathematical concept swapped in for another, ask ...”
November 2, 2018
ceilidh.erickson posted a reply to The difference in average annual income in (OG18) help in the GMAT Verbal & Essays forum
“If we want to WEAKEN an argument, we must first find the logical flaws - the missing information - between the premises and the conclusion. Premises: The difference in average annual income in favor of employees who have college degrees, compared with those who do not have such degrees, doubled ...”
November 2, 2018
GMATGuruNY posted a reply to Ryunosuke Akutagawa in the Sentence Correction forum
“Nicely done! Because the comparison in D allows for more than one logical interpretation, eliminate D. In fact, the ambiguity cited above is the most compelling reason to eliminate D.”
November 2, 2018
GMATGuruNY posted a reply to Ryunosuke Akutagawa in the Sentence Correction forum
“X led to Y implies that X did not directly cause Y but that X was a factor that helped to yield Y. SC755 in the OG17: An inability to adapt led to their extinction. Here, an inability to adapt did not directly cause the extinction but was a factor that helped to yield the extinction. A cause ...”
November 2, 2018
GMATGuruNY posted a reply to Ryunosuke Akutagawa in the Sentence Correction forum
“Generally, COMMA + as-clause implies that the clause after as LEADS to the preceding clause, with the result that the two clauses happen concurrently. An OA in GMATPrep: The steel industry has changed radically over the last two decades, as large, integrated companies such as Bethlehem Steel have ...”
November 2, 2018
GMATGuruNY posted a reply to Barry walks from one end to the other of a 30-meter long in the Problem Solving forum
“Let B = Barry''s rate and W = the walkway''s rate. The distance can be ANY VALUE. Let the distance = 240 meters. WITH the walkway, the time = 30 seconds: Here, Barry and the walkway WORK TOGETHER, so we ADD their rates: B+W = d/t = 240/30 = 8 meters per second. AGAINST the walkway, the ...”
November 2, 2018
ceilidh.erickson posted a reply to What is the area of the trapezoid shown? in the Data Sufficiency forum
“Poster, can you clarify where you found this? I don''t recognize this problem, and I can''t find it in any of our materials. I think it''s unlikely that this is actually a Manhattan Prep question.”
November 1, 2018
ceilidh.erickson posted a reply to A market research company surveyed users of the toothpaste in the Data Sufficiency forum
“We''re given that everyone in the survey used at least one of Brand X and Brand Y. We can think of this as: (Brand X users) + (Brand Y users) - (people who used both) = Total or, since we''re asked for a percentage: X + Y - B = 100 If we want to know the percentage who used Brand Y, we''ll ...”
November 1, 2018
ceilidh.erickson posted a reply to Lyme disease is caused by a bacterium transmitted to humans in the Critical Reasoning forum
“Whenever you''re asked to STRENGTHEN or WEAKEN an argument, it''s implied that there is a logical flaw - a missing piece - in the argument. Break down the argument carefully and identify what''s missing before diving into the answer choices. Premises: - deer ticks pick up Lyme bacterium while ...”
November 1, 2018
GMATGuruNY posted a reply to At a family summer party, each of the x members of the in the Problem Solving forum
“Let the x family members = the product of the two denominators = 3*7 = 21. Number who chose to have a hamburger = (1/3)(21) = 7. Since 1/7 of the hamburger-eaters also had a hot dog, the number who had both = (1/7)(7) = 1. Thus, the number who did NOT have both = (total members) - (number who had ...”
November 1, 2018
GMATGuruNY posted a reply to How many positive five-digit integers contain the digit in the Problem Solving forum
“I believe that the prompt above is outdated; regardless, it does not list a correct answer. The prompt below appears in Manhattan''s 5 lb. Book of GRE Practice Problems: Case 1: 57XXX Number of options for the hundreds digit = 10. (Any digit 0-9.) Number of options for the tens digit = 10. ...”
November 1, 2018
GMATGuruNY posted a reply to Two teachers, Ms. Ames and Mr. Betancourt, each had N in the Data Sufficiency forum
“Since the N cookies can be divided evenly among 24 or 18 students, N must be divisible by both 24 and 18. One way to determine the LCM of two integers is to take multiples of the LARGER integer until we get a multiple of the SMALLER integer. Multiples of 24: 24, 48, 72... We can stop here: the ...”
November 1, 2018
GMATGuruNY posted a reply to Did one of the 3 members of a certain team sell at least 2 in the Data Sufficiency forum
“Statement 1: If NONE of the members sells at least 2 tickets, then the 3 members sell a maximum of 1 ticket each, yielding the following total: 1+1+1 = 3. Too small, since the total number of tickets sold = 6. Implication: For a total of 6 tickets to be sold, one of the 3 members must sell at ...”
October 31, 2018
GMATGuruNY posted a reply to A football team averaged 35 points per game over the first in the Problem Solving forum
“This is a weighted average/mixture problem. Average score for the first N games = 35. Score for the final game = 28. Average score for the MIXTURE of all the games = 34. Step-by-step instruction for the alligation approach: Step 1: Plot the 3 averages on a number line, with the average ...”
October 31, 2018
ceilidh.erickson posted a reply to In countries where automobile insurance includes in the Critical Reasoning forum
“By the way, it''s interesting to note that the GMAT will sometimes use the same argument but ask different questions about it. Here is the same argument from the OG, but with different portions bolded: ...”
October 31, 2018
ceilidh.erickson posted a reply to In countries where automobile insurance includes in the Critical Reasoning forum
“The goal in any BOLDFACE question is to deconstruct the argument, and determine the role of each statement: - author''s conclusion / position - support for the author - the counterpoint / what others believe - support for the counterpoint - neutral / background information This ...”
October 31, 2018
GMATGuruNY posted a reply to 3, 6, 9, 12, … are multiples of 3. How many multiples of 3 in the Problem Solving forum
“The difference between the endpoints of the range = 200-10 = 190. Since neither endpoint is a multiple of 3, we can count the multiples of 3 simply by dividing 3 into 190: 190/3 ≈ 63. The correct answer is D.”
October 31, 2018
GMATGuruNY posted a reply to A group of 20 friends formed an investment club, with each in the Problem Solving forum
“Let d=100. After the value of the stock increases by 40% to $140, the share received by each of the 20 friends = 140/20 = 7. The correct answer must yield a value of 7 when d=100. Only E works: (7d)/100 = (7*100)/100 = 7. The correct answer is E.”
October 30, 2018
GMATGuruNY posted a reply to The average weight of a class is x pounds. When a new in the Problem Solving forum
“We can PLUG IN THE ANSWERS and use alligation. To learn about alligation, check my posts here: https://www.beatthegmat.com/statistics-average-question-t288903.html https://www.beatthegmat.com/alligation-method-t293459.html https://www.beatthegmat.com/mean-t266852.html Let O = the original ...”
October 30, 2018
GMATGuruNY posted a reply to Machines X and Y can work at their respective constant rates in the Data Sufficiency forum
“Statement 1: Time and rate have a RECIPROCAL relationship. Since X and Y together take 2/3 as long as Y alone, X and Y together work 3/2 as fast as Y alone. Thus, if Y''s rate alone = 2 units per hour, then X and Y''s combined rate = (3/2)(2) = 3 units per hour, implying that X''s rate alone = ...”
October 30, 2018
GMATGuruNY posted a reply to Set S contains nine distinct points in the coordinate plane. in the Problem Solving forum
“To form a triangle, we must select 3 points such that at most 2 are collinear. Case 1: Select 3 points not on the x-axis From the 4 points not on the x-axis, the number of ways to choose 3 = 4C3 = (4*3*2)/(3*2*1) = 4. Case 2: Select 1 point on the x-axis and two points not on the x-axis From ...”
October 29, 2018
GMATGuruNY posted a reply to Employees at a company will vote for an executive team of in the Problem Solving forum
“Number of options for president = 8. (Any of the 8 candidates.) Number of options for treasurer = 7. (Any of the 7 remaining candidates.) From the 6 remaining people, the number of ways to choose 3 to serve as warrant officers = 6C3 = (6*5*4)/(3*2*1) = 20. To combine these options, we multiply: ...”
October 29, 2018
GMATGuruNY posted a reply to A set of pencils can be evenly shared between 2, 3, 4, 5 and in the Problem Solving forum
“For the set of pencils to be shared evenly, the total number of pencils must be divisible by the total number of children. Thus, the correct answer must be divisible by 2, 3, 4, 5 and 6. Of the five answer choices, only E is divisible by 2, 3, 4, 5 and 6. The correct answer is E.”
October 29, 2018
GMATGuruNY posted a reply to (x^2-3x+2)(y^2-5y+6)=? in the Data Sufficiency forum
“Statement 1: Substituting x=1 into (x² - 3x + 2)(y² - 5x + 6), we get: (1 - 3*1 + 2)(y² - 5x + 6) = (0)(y² - 5x + 6) = 0. SUFFICIENT. Statement 2: Substituting y=1 into (x² - 3x + 2)(y² - 5x + 6), we get: (x² - 3x + 2)(1² - 5*1 + 6) = (x² - 3x + 2)(2). Since the value of x is ...”
October 29, 2018
GMATGuruNY posted a reply to How many integers are there between, but not including, in the Data Sufficiency forum
“Statement 1: Case 1: r=0 and s=10 Integers between r and s: 1, 2, 3, 4, 5, 6, 7, 8, 9 --> 9 integers Case 2: r=1 and s=11 Integers between r and s: 2, 3, 4, 5, 6, 7, 8, 9, 10 --> 9 integers Case 3: r=2 and s=12 Integers between r and s: 3, 4, 5, 6, 7, 8, 9, 10, 11 --> 9 ...”
October 28, 2018
GMATGuruNY posted a reply to Both Betty and Wilma earn annual salaries of more than $5000 in the Data Sufficiency forum
“Statement 1: Betty''s annual salary is closer to $50000 than Wilma''s is. On a number line: -----50,000---B---W Thus, W > B. SUFFICIENT. Statement 2: Betty''s annual salary is closer to $35000 than it is to Wilma''s annual salary. Case 1: -----35,000-----50,000---B---W Case 2: ...”
October 28, 2018
GMATGuruNY posted a reply to In a right triangle, the longer leg is two more than three in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the length of the shorter leg. When the correct answer is plugged in, the area = 400. B: 20 Longer leg = two more than three times the shorter leg = 2 + 3*20 = 62. Area = (1/2)(20)(62) = 620. Since the area is too great, a smaller answer choice is ...”
October 27, 2018
GMATGuruNY posted a reply to A framed picture is shown above. The frame, shown shaded, is in the Data Sufficiency forum
“Statement 1: Test one case that also satisfies Statement 2. Case 1: The frame is 8 inches tall, with the result that the total area of the frame and picture combined = 6*8 = 48 Area of the picture = (total area) - (shaded region) = 48-24 = 24. Implication: The width of the frame is 1 inch, ...”
October 27, 2018
GMATGuruNY posted a reply to What is the largest prime factor of the expression 3^8 − 2 in the Problem Solving forum
“A general rule: Given x^(even power) - y^(even power), where x and y are distinct positive integers, we can always simplify by applying the difference of two squares. Each time we apply the difference of two squares to the expression in blue, the exponents are reduced by 1/2. For example: x⁸ - ...”
October 26, 2018
GMATGuruNY posted a reply to Jazz and blues recordings accounted for 6 percent of the in the Data Sufficiency forum
“Let J = jazz and blues revenue in 1998. Statement 1: Case 1: Total revenue in 1998 = 100 In this case, J = 5% of 100 = 5. Case 2: Total revenue in 1998 = 1000 In this case, J = 5% of 1000 = 50. Since J can be different values, INSUFFICIENT. Statement 2: In other words: (jazz and blues ...”
October 26, 2018
GMATGuruNY posted a reply to x and y are non-negative integers. If xy+2x+3y=0, then y=? in the Problem Solving forum
“NONNEGATIVE implies that we should test ZERO. Let x=0. Substituting x=0 into xy + 2x + 3y = 0, we get: 0*y + 2*0 + 3y = 0 3y = 0 y = 0 The correct answer is A.”
October 26, 2018
GMATGuruNY posted a reply to Set S contains consecutive natural numbers from 1 to 100, in in the Problem Solving forum
“For any evenly spaced set: sum = (count)(median) Sum of the first n even numbers = n * median of the first n even numbers Sum of the last n odd numbers = n * median of the last n odd numbers Since the ratio of the two sums = 16/85, we get: (n * median of the first n even numbers) / (n * ...”
October 26, 2018
GMATGuruNY posted a reply to Quentin's income is 60% less than Rex's income, and Sam's in the Problem Solving forum
“Let Rex''s income = 100. Since Quentin''s income is 60% less than Rex''s, Quentin''s income = 100 - (60% of 100) = 100-60 = 40. Since Sam''s income is 25% less than Quentin''s, Sam''s income = 40 - (25% of 40) = 40-10 = 30. After Rex gives 60% of his income to Sam, Sam''s new income = 30 + (60% ...”
October 25, 2018
GMATGuruNY posted a reply to If |x-6|=2x, then x=? in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the value of x. Since an absolute value cannot be equal to a negative value, the correct answer cannot be A or B. D: x=2 If we plug x=2 into |x-6|=2x, we get: |2-6| = 2*2 |-4| = 4 4 = 4. Success! The correct answer is D.”
October 25, 2018
GMATGuruNY posted a reply to Tom drives from town A to town B, driving at a constant in the Problem Solving forum
“Let the distance between A and B = 120 miles. Since the 120-mile distance between A and B is twice the distance between B and C, the distance between B and C = 60 miles, implying that the total distance = 120+60 = 180 miles. Since the average speed for the 120-mile leg between A and B = 60 mph, ...”
October 25, 2018
GMATGuruNY posted a reply to gmat prep 2 in the Critical Reasoning forum
“The negation test is not recommended for Evaluate CRs. It can be applied to Assumption CRs and Inference CRs.”
October 24, 2018
GMATGuruNY posted a reply to Computer-based activities in the Critical Reasoning forum
“The answer choices are already phrased as statements. The OA is a statement that weakens the conclusion. OA: Computer owners in the United States predominately belong to a demographic group that have long been known to spend less time watching television. This statement indicates that a lack of ...”
October 24, 2018
GMATGuruNY posted a reply to Noelle walks from point A to point B at an average speed of in the Problem Solving forum
“Let the distance between A and B = the LCM of the two speeds = 5*6 = 30 kilometers, implying that the distance for the entire round trip = 60 kilometers. At a rate of 5 kph, the time to travel the 30 kilometers from A to B = d/r = 30/5 = 6 hours. At a rate of 6 kph, the time to travel the entire ...”
October 24, 2018
GMATGuruNY posted a reply to What is the median number of employees assigned per project in the Data Sufficiency forum
“In ascending order of EMPLOYEES PER PROJECT, let the projects be numbered 1 through 100: 1, 2, 3.....49, 50, 51, ....98, 99, 100. Projects 50 and 51 determine the MEDIAN number of employees: Question rephrased: How many employees are assigned to PROJECTS 50 and 51? Looking at the two ...”
October 24, 2018
GMATGuruNY posted a reply to Three photographers , Lisa, Mike and Norm, take photos of a in the Problem Solving forum
“The sum for Lisa and Mike is 50 less than the sum for Norm and Mike. Since Mike is common to both sums, the 50-photo difference must be yielded solely by Lisa and Norm. Implication: Lisa took 50 fewer photos than Norm. We can PLUG IN THE ANSWERS, which represent the number of photos taken by ...”
October 24, 2018
GMATGuruNY posted a reply to Circle ABCD in the diagram above is defined by the equation in the Problem Solving forum
“Circle ABCD: The equation for a circle with a center at the origin and a radius of r is x² + y² = r². The equation for circle ABCD is x² + y² = 5². Thus, circle ABCD has a radius of 5. Line EF: 3y = 4x + 25 y = (4/3)x + 25/3 Slope = 4/3. A radius drawn to a point of tangency forms ...”
October 24, 2018
ceilidh.erickson posted a reply to At a constant speed of 72 kilometers per hour, a vehicle in the Problem Solving forum
“"Units Control" has a great space-age ring to it, like something you''d shout from the bridge on Star Trek! I like it.”
October 23, 2018
ceilidh.erickson posted a reply to A factory has three types of machines, each of which works in the Problem Solving forum
“Fabio, I definitely agree with your sentiment generally! But Mitch & I have worked side by side for years, with much mutual respect (I''m assuming!). I''ve never known him to knowingly step on anyone''s toes. I''m sure we''ve all had the experience of someone else posting while we were in the ...”
October 23, 2018
GMATGuruNY posted a reply to A factory has three types of machines, each of which works in the Problem Solving forum
“In many cases, similar or identical solutions are posted when two experts respond at virtually the same time, with the result that the second poster is not aware of the first. The time stamps for the two solutions here indicate that both solutions were posted at 11:45am.”
October 23, 2018
ceilidh.erickson posted a reply to Although the earliest surviving Greek inscriptions written in the Critical Reasoning forum
“For more on CR Boldface questions, see: https://www.beatthegmat.com/gmat-official-guide-2019-boreal-owls-range-over-a-much-t303663.html#818059 https://www.beatthegmat.com/gmat-official-guide-2019-in-countries-where-automobile-t303686.html#818265 ...”
October 23, 2018
ceilidh.erickson posted a reply to Although the earliest surviving Greek inscriptions written in the Critical Reasoning forum
“With BOLDFACE questions in CR, break down the argument according to the following roles: - author''s conclusion - supporting premises - counterpoint / someone else''s conclusion - support for the counterpoint - general phenomena / neutral facts We can break down this argument as follows: ...”
October 23, 2018
ceilidh.erickson posted a reply to While political discourse and the media in the United States in the Critical Reasoning forum
“If we want to EVALUATE an argument, we must first figure out where the argument is flawed: we must find a missing link between premises & conclusion. Conclusion: The drop in enrollment of foreign-born graduate students since 2001 will hurt America’s competitiveness in basic research and ...”
October 23, 2018
ceilidh.erickson posted a reply to If x and y are positive integers, what is the remainder when in the Data Sufficiency forum
“It''s important to note here that certain digits will always maintain the same units digit, regardless of the exponent: 0, 1, 5, and 6. All other digits [2, 3, 4, 7, 8, and 9] will change units digits, depending on the exponent. More on establishing those patterns here: ...”
October 23, 2018
ceilidh.erickson posted a reply to If Machine B and Machine C work together at their constant in the Data Sufficiency forum
“Machines working together will work at the SUM of their individual rates. Since the question is asking us for the proportion of the work that Machine B completed, we would need to know the proportion that A & C together completed. (1) Machine A and Machine B, working together at their ...”
October 23, 2018
ceilidh.erickson posted a reply to At a constant speed of 72 kilometers per hour, a vehicle in the Problem Solving forum
“For more on doing unit conversions correctly, see: https://www.manhattanprep.com/gmat/blog/2016/01/20/heres-how-to-do-gmat-unit-conversions-like-a-pro/ https://www.manhattanprep.com/gmat/blog/2013/01/14/remember-your-units/”
October 23, 2018
ceilidh.erickson posted a reply to At a constant speed of 72 kilometers per hour, a vehicle in the Problem Solving forum
“Here''s an easy way to set up UNIT CONVERSIONS - set it up as fractions, so that numerators and denominators of the same unit cancel: https://i.postimg.cc/JD8nxJtz/Screenshot-2018-10-23-12-18-55.png https://i.postimg.cc/cKR1vHTy/Screenshot-2018-10-23-12-20-01.png Now there''s no confusion ...”
October 23, 2018
GMATGuruNY posted a reply to A factory has three types of machines, each of which works in the Problem Solving forum
“Rates can be ADDED TOGETHER. 7 Machine As and 11 Machine Bs can produce 250 widgets per hour. 7A + 11B = 250 8 Machine As and 22 Machine Cs can produce 600 widgets per hour. 8A + 22C = 600 4A + 11C = 300 Adding together 7A + 11B = 250 and 4A + 11C = 300, we get: 11A + 11B + 11C = 550 A ...”
October 23, 2018
ceilidh.erickson posted a reply to A factory has three types of machines, each of which works in the Problem Solving forum
“At first, it might seem as if we don''t have enough information to solve. We have 3 unknowns (the rates of Machines A, B, and C), but only 2 equations. Since this is Problem Solving and not Data Sufficiency, though, (and there is no "cannot be determined" answer) there must be some way to ...”
October 23, 2018
GMATGuruNY posted a reply to 25 integers are written on a board. Are there at least two in the Data Sufficiency forum
“The wording in Statement 1 does not convey a clear meaning: For every value in the list, if the value is increased by 1, the number of distinct values in the list does not change. Here, the term in red could convey to some test-takers that EVERY VALUE in the list is to be increased by 1. Not the ...”
October 23, 2018
GMATGuruNY posted a reply to The annual rent collected by a corporation from a certain in the Data Sufficiency forum
“Let the 1997 rent = 100. Increase in 1998 = (x/100)(100) = x. Thus, rent in 1998 = 100+x. Decrease in 1999 = (y/100)(100+x) = y + xy/100 For the rent to be greater in 1999 than in 1997, the increase in 1998 (x) must be greater than the decrease in 1999 (y + xy/100). Question stem, ...”
October 21, 2018
GMATGuruNY posted a reply to During a 3 year period, the profits of company X changed by in the Data Sufficiency forum
“Statement 1: If profits increase by $X from the first year to the second year, then they must increase by $0 from the second year to the third year, with the result that the increase in profits from the first year to the third year (X+0 = $X) is the same as the increase in profits from the first ...”
October 21, 2018
GMATGuruNY posted a reply to OG The estimated number of homeschooled students in the Problem Solving forum
“Percent greater or percent increase: (bigger value - smaller value)/(smaller value) * 100 Percent less or percent decrease: (bigger value - smaller value)/(bigger value) * 100”
October 21, 2018
GMATGuruNY posted a reply to Mark has fewer than 9 coins. Each coin is either a quarter in the Data Sufficiency forum
“Statement 1: 25Q + 10D = 170 5Q + 2D = 34 To minimize the number of coins, we must maximize the value of Q. If Q=6, then D=2, with the result that 5Q + 2D = (5*6) + (2*2) = 34. In this case, the total number of coins = 6+2 = 8. If the value of Q decreases, then the total number of coins will ...”
October 20, 2018
GMATGuruNY posted a reply to doubt 3 in the Sentence Correction forum
“having + VERBed is a viable construction. An introductory HAVING + VERBed modifier implies PRIOR ACTION: an action completed before the main verb. HAVING FINISHED his dessert, John LEFT the table. Here, HAVING FINISHED implies PRIOR ACTION -- an action completed before John LEFT the table. ...”
October 20, 2018
GMATGuruNY posted a reply to All attendees at a university gathering are faculty or in the Data Sufficiency forum
“Neither statement offers any information about the number of attendees who are alumni. Thus, the two statements combined are INSUFFICIENT. The correct answer is E.”
October 20, 2018
GMATGuruNY posted a reply to If n is an integer, which of the following must be divisible in the Problem Solving forum
“Test n=0. A --> n³ - 4n = 0³ - (4*0) = 0 B --> n³ + 4n = 0³ + (4*0) = 0 C --> n² + 1 = 0² + 1 = 1 D --> n² - 1 = 0² - 1 = -1 E --> n² - 4 = 0² - 4 = -4 Only the options in green yield a multiple of 3. Eliminate C, D and E. Test n=1 in the remaining answer ...”
October 20, 2018
GMATGuruNY posted a reply to At a certain industrial manufacturer, an open tank contains in the Problem Solving forum
“Since 6% of the 1000-gallon tank is fluorine, the amount of fluorine = (6/100)(1000) = 60 gallons. Since the total volume decreases at a rate of 10 gallons per day for 25 days, the decrease in the total volume = 10*25 = 250 gallons. Remaining total volume = 1000-250 = 750 gallons. Since 60 of the ...”
October 20, 2018
GMATGuruNY posted a reply to Is 1+x+x^2+x^3+x^4+x^5+x^6 < 1/(1-x)? in the Data Sufficiency forum
“CRITICAL POINTS in an equality occur when the two sides are EQUAL or the inequality is undefined. Here, the two statements provide the critical points for the inequality in the prompt: When x=0, the two sides are equal. When x=1, the inequality is undefined. To determine the range(s) where the ...”
October 20, 2018
GMATGuruNY posted a reply to Did Jeff record more sales revenue this month than Dan did? in the Data Sufficiency forum
“Statement 1: For every $100 commission that Dan earns, Jeff earns $120 in commission. Since the commission rates for Dan and Jeff are unknown, no way to determine whether Jeff recorded more sales revenue than Dan. INSUFFICIENT. Statement 2: Since Jeff''s sales and Dan''s sales can be any ...”
October 19, 2018
GMATGuruNY posted a reply to If a rectangle’s length is a+b and its area is (1/a)+(1/b) in the Problem Solving forum
“Let a=b=0.5, implying that the rectangle''s length = a+b = 0.5+0.5 = 1 and that its area = (1/0.5) + (1/0.5) = (10/5) + (10/5) = 2+2 = 4. Since the rectangle has an area of 4 and a length of 1, its width = 4. The correct answer must yield a value of 4 when a=b=0.5. Only E works: 1/ab = 1/(0.5 * ...”
October 19, 2018
GMATGuruNY posted a reply to When positive integer N is divided by positive integer J, in the Problem Solving forum
“N/J = 134.08 = 13408/100 = 3352/25. The resulting ratio indicates that N must be multiple of 3352 and that J must be a multiple of 25. Of the five answer choices, only E is a multiple of 25. The correct answer is E.”
October 19, 2018
GMATGuruNY posted a reply to A container contains 4 red marbles and 8 blue marbles. in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the number of blue marbles in the second container. When the correct answer is plugged in, the probability of selecting 2 red marbles OR 2 blue marbles = 1/2. B: 4 blue marbles, implying a total of 10 marbles in the second container Case1: 2 red ...”
October 19, 2018
GMATGuruNY posted a reply to Two printing presses begin printing currency at the same in the Problem Solving forum
“Since F produces 1000 5-dollar bills each minute, the dollar amount produced by F each minute = 1000*5 = $5000. Since T produces 200 20-dollar bills each minute, the dollar amount produced by T each minute = 200*20 = $4000. Thus, every minute F surpasses T by $1000. Since F surpasses T by $1000 ...”
October 18, 2018
GMATGuruNY posted a reply to Brian purchased a bouquet of 40 flowers for his mother for in the Problem Solving forum
“= We can PLUG IN THE ANSWERS, which represent the number of tulips. When the correct answer is plugged in, the total cost = $48. D: 24 tulips, implying 16 roses, for a total of 40 flowers Since each of the 24 tulips costs $1, and each of the 16 roses costs $1.50, we get: Total cost = (24*1) ...”
October 18, 2018
ceilidh.erickson posted a reply to The heignt of an equilateral triangle is the side of a in the Problem Solving forum
“Very well said! And thank you ;)”
October 16, 2018
ceilidh.erickson posted a reply to The heignt of an equilateral triangle is the side of a in the Problem Solving forum
“Well thanks, you made my day, too! We''re all here to learn from each other & share what we know, right? I''ve always found it weird and transparent when people try to "talk over" each other in forums like this. Much better to act like collaborators!”
October 16, 2018
ceilidh.erickson posted a reply to The heignt of an equilateral triangle is the side of a in the Problem Solving forum
“Yes, good point! I didn''t include it in my diagram, but we can''t just assume it''s 90 - we have to justify it with the reasoning Fabio outlined.”
October 16, 2018
ceilidh.erickson posted a reply to If x, y, and z are all nonzero numbers, and x = y + z, which in the Problem Solving forum
“We can also rearrange the equation algebraically. If x = y + z, then: y = x - z z = x - y Compare these to our answer choices: (A) (y - z)/x We know that y + z = x, so (y + z)/x = 1. If all terms are non-zero, then there''s no way that y + z = y - z, so (y - z)/x must not equal 1. (B) ...”
October 16, 2018
ceilidh.erickson posted a reply to The heignt of an equilateral triangle is the side of a in the Problem Solving forum
“Here''s an easier way to look at it: we''ve created another 30-60-90 triangle between A, B, and the midpoint of the base of the larger triangle. If the base = 1, then half the base = 1/2. This is the hypotenuse of the right triangle. Thus, AB must be half that length: 1/4. ...”
October 16, 2018
ceilidh.erickson posted a reply to What is the remainder if 7^10 is divided by 100? in the Problem Solving forum
“A general note: the GMAT will often use "remainder when divided by 10" as code for "units digit," or "remainder when divided by 100" as "the last 2 digits." Here are more examples along those lines: ...”
October 16, 2018
ceilidh.erickson posted a reply to Among the Tsonga, a Bantu-speaking group of tribes in in the Sentence Correction forum
“This question is primarily testing IDIOMS and meaning. Among the Tsonga, a Bantu-speaking group of tribes in southeastern Africa, dance teams represent their own chief at the court of each other, providing entertainment in return for food, drink, and lodging. (A) the court of each other, ...”
October 16, 2018
ceilidh.erickson posted a reply to The pioneering research of Lewis Latimer and Thomas Edison, in the Sentence Correction forum
“A. of Lewis Latimer and Thomas Edison, who became known for his invention of the light bulb, - when "who" follows "Lewis Latimer and Thomas Edison", it should modify both of them. Since it continues "his invention," we must rearrange the sentence so that we''re only ...”
October 16, 2018
ceilidh.erickson posted a reply to A popular beach has long had a dolphin feeding program in in the Critical Reasoning forum
“Here is the general process you should use for EXPLAIN DISCREPANCY problems: 1. Evaluate the given circumstance / phenomenon. 2. Think about what you would have expected / what the normal outcome would likely have been (this is usually unstated). 3. Think about why that''s at odds with the ...”
October 16, 2018
ceilidh.erickson posted a reply to Beat the GMAT! 760 in just over 4 weeks in the I just Beat The GMAT! forum
“I would strongly urge everyone on this forum NOT to follow this poster''s sleep regimen. This poster may think that reducing sleep contributed to his success, but it likely did more harm than good. The GMAT is not a test you can cram for. Very broadly speaking, cramming stores a lot of ...”
October 16, 2018
GMATGuruNY posted a reply to A certain NYC taxi driver has decided to start charging a in the Problem Solving forum
“Let r=100 cents. For 3 people, the cost per mile = 3*100 = 300 cents = 3 dollars. Let x = 2 miles. Regular cost for 3 people to travel 2 miles = 3*2 = 6 dollars. With a 50% discount, the cost in dollars = 3. This is the target. Plug x=2 and r=100 into the answers to see which yields the ...”
October 16, 2018
GMATGuruNY posted a reply to (1-1/10)(1-1/11)(1-1/12)…(1-1/100) =? in the Problem Solving forum
“(1-1/10)(1-1/11)(1-1/12)…(1-1/99)(1-1/100) = (9/10)(10/11)(11/12)....(98/99)(99/100). The values in blue all cancel out, leaving only the values in red: 9/100. The correct answer is C.”
October 16, 2018
GMATGuruNY posted a reply to A rectangular garden is to be twice as long as it is wide. in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the length. When the correct answer is plugged in, perimeter = 360. B: 140 Since the length is twice the width, W = 70, with the result that the perimeter = 140+140+70+70 = 420. Since the perimeter is too great, a SMALLER answer choice is needed. ...”
October 16, 2018
GMATGuruNY posted a reply to Is the sum of 7 different positive integers greater than or in the Data Sufficiency forum
“Statement 1: Least possible case: 1+2+3+9+10+11+12 = 48. Since the least possible case is greater than or equal to 48, the answer to the question stem is YES. SUFFICIENT. Statement 2: Least possible case: 1+2+3+4+5+6+12 = 33. Greatest possible case: 6+7+8+9+10+11+12 = 63. Since the answer ...”
October 16, 2018
GMATGuruNY posted a reply to If x, y, and z are all nonzero numbers, and x = y + z, which in the Problem Solving forum
“x = y + z is valid if x=2, y=1 and z=1. The correct answer must yield a value of 1 when x=2, y=1 and z=1. Only E works: (x-z)/y = (2-1)/1 = 1. The correct answer is E.”
October 16, 2018
GMATGuruNY posted a reply to If |x+1|=2|x-1|, x=? in the Data Sufficiency forum
“Case 1: Signs unchanged x+1 = 2(x-1) x+1 = 2x-2 3 = x Case 2: Signs changed on ONE SIDE -x-1 = 2(x-1) -x-1 = 2x-2 1 = 3x 1/3 = x Resulting solutions: x=3 or x=1/3 Statement 1: Since x < 1, only x=1/3 is a viable solution. SUFFICIENT. Statement 2: Since x>0, both x=1/3 ...”
October 15, 2018
GMATGuruNY posted a reply to Lindsay can paint 1/x of a certain room in one hour. If in the Problem Solving forum
“Let the room = 20 units. Let x = 4. Since Lindsay paints 1/x of the room in 1 hour, Lindsay''s rate = (1/4) * 20 = 5 units per hour. Since Lindsay and Joseph paint the entire room in 1 hour, their combined rate = 20 units per hour. Thus, Joseph''s rate = (combined rate) - (Lindsay''s rate) ...”
October 15, 2018
GMATGuruNY posted a reply to The principal feature of the redesigned checks is a series o in the Sentence Correction forum
“Generally, a COMMA + VERBing modifier serves to modify the nearest preceding action and the agent of this action. C: instructions that...will help merchants confirm a check''s authenticity, by including reminders to watch the endorsement. .Here, COMMA + by including seems to modify merchants ...”
October 15, 2018
GMATGuruNY posted a reply to What is the remainder if 7^10 is divided by 100? in the Problem Solving forum
“When a positive integer is divided by 100, the remainder is yielded by the last two digits: 123/100 = 1 R23 548/100 = 5 R48 692/100 = 6 R92 Thus: The remainder when 7¹⁰ is divided by 100 is equal to the last two digits of 7¹⁰. Calculate the last two digits for consecutive powers of 7 ...”
October 14, 2018
GMATGuruNY posted a reply to Alice, Barbara, and Cynia work on identical tasks at differe in the Data Sufficiency forum
“TIME and RATE have a reciprocal relationship. Statement 1: The time ratio for Barbara and Alice = (14 hours)/(21 hours). The rate ratio for Barbara and Alice is equal to the reciprocal of the time ratio: (B''s rate)/(A''s rate) = 21/14 = 3/2. Let B = 3 units per hour and A = 2 units per ...”
October 13, 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 ...”
October 13, 2018
GMATGuruNY posted a reply to A certain club has 10 members, including Harry. One of the 1 in the Problem Solving forum
“Each of the 10 members has an EQUAL chance of being elected secretary. P(Harry is elected secretary) = 1/10. Each of the 10 members has an EQUAL chance of being elected treasurer. P(Harry is elected treasurer) = 1/10. Since EITHER outcome is favorable, we ADD the fractions: 1/10 + 1/10 = 2/10 = ...”
October 13, 2018
GMATGuruNY posted a reply to Challenge question: What is the sum of all in the Problem Solving forum
“x^(2/3) - x^(1/3) - 2 = 4 x^(2/3) - x^(1/3) - 6 = 0 D.”
October 12, 2018
October 12, 2018
GMATGuruNY posted a reply to Hard Assumption - Manhattan in the Critical Reasoning forum
“The conclusion is constrained to the case at hand: Of the 10 babies recently placed with parents, 8 were given to friends of the staff. The assumption is that the premise (the parents given babies -- including the 8 friends --all far surpassed the agency''s criteria) is sufficient to prove the ...”
October 11, 2018
ceilidh.erickson posted a reply to Strategy to score 700+ in the GMAT Verbal & Essays forum
“I''m not really sure what you''re asking here. You say that you don''t have time or energy to prep, but then you''re asking for advice about how get a 700? If there were a magical shortcut to a 700, everyone would take it, and there would be no need for prep programs. The way to get a 700 is to ...”
October 11, 2018
ceilidh.erickson posted a reply to GMAT preparation Group at 42 in the Let's Meet Up forum
“The most important thing is to determine *why* you want an MBA at this age. Why not an EMBA? If you''re seeking to level up your skills, there may be ways to do that outside of a full-time program. It''s generally the case that elite MBA programs want to accept students who are relatively early ...”
October 11, 2018
ceilidh.erickson posted a reply to DS: Difficulty level: 700, Source: GMATPrep in the GMAT Math forum
“The square root of a square is a coded way of saying absolute value. Whether the base is positive or negative, squaring will make it positive, and when given a root sign, we only take the positive root: https://i.postimg.cc/PN1FGTXN/Screenshot-2018-10-11-15-57-39.png So, we can rephrase the ...”
October 11, 2018
GMATGuruNY posted a reply to If every boy in a kindergarten class buys a soda and every in the Problem Solving forum
“Let: b = the number of boys g = the number of girls s = the number of cents for each soda j = the number of cents for each juice box Note: All of the values above must be POSITIVE INTEGERS. Case One: If every boy in a kindergarten class buys a soda and every girl in the same class buys a ...”
October 11, 2018
ceilidh.erickson posted a reply to Full time student in the GMAT Strategy forum
“If you''re finding that the Mprep Foundations guides are easy, then move on to the strategy guides. I''d recommend doing a handful of the drill sets at the end of each chapter in the Foundations guides to test your knowledge / build your basic muscles back up, but you can probably skip reading the ...”
October 11, 2018
GMATGuruNY posted a reply to Julie opened a lemonade stand and sold lemonade in two in the Data Sufficiency forum
“Let X = the number of 52¢ lemonades and Y = the number of 58¢ lemonades. Since the question stem asks for the number of 52¢ lemonades, we get: What is the value of X? Statement 1: X+Y = 9 Since X can be any value between 0 and 9, inclusive, INSUFFICIENT. Statement 2: 52X + 58Y = 492 ...”
October 11, 2018
GMATGuruNY posted a reply to For the students in a Physical Fitness Class Section #1, the in the Data Sufficiency forum
“Range = highest - lowest. Thus: Lowest = highest - range. In Section 1, lowest = highest - range = X-R. In Section 2, lowest = highest - range = Y-S. If the lowest weight in Section 1 is greater than the lowest weight in Section 2, we get: X-R > Y-S X+S > Y+R. Question ...”
October 11, 2018
GMATGuruNY posted a reply to Angela’s grade was in the 90th percentile out of 80 grades in the Problem Solving forum
“Percentile means the percentage below: (total below)/(total grades) * 100. Angela''s 80-student class: Since Angela''s grade was in the 90th percentile, 90% of the grades were below Angela''s: (90/100)(80) = 72. 100-student class: Since 19 grades were higher than Angela''s, the remaining ...”
October 10, 2018
GMATGuruNY posted a reply to There are 5 cars to be displayed in 5 parking spaces with in the Problem Solving forum
“Alternate approach: The 3 red cars must occupy a combination of 3 spaces. From 5 spaces, the number of ways to choose a combination of 3 for the red cars = 5C3 = (5*4*3)/(3*2*1) = 10. Number of options for the blue car = 2. (Either of the 2 remaining spaces.) Number of options for the yellow ...”
October 10, 2018
GMATGuruNY posted a reply to Hard Assumption - Manhattan in the Critical Reasoning forum
“Premise: All of the applicants given babies far surpassed the adoption criteria. Conclusion: In placing 8 of the 10 babies with friends, the staff was not guilty of favoritism. Apply the NEGATION TEST. When the correct answer is negated, the conclusion will be invalidated. B, negated: Of ...”
October 10, 2018
GMATGuruNY posted a reply to A group of medical interns at Bohemus Medical School want to in the Problem Solving forum
“In other words: How many ways can 5 girls and 5 guys be divided into pairs, if each pair must consist of one girl and one guy? Number of options for the first girl = 5. (Any of the 5 guys.) Number of options for the second girl = 4. (Any of the 4 remaining guys). Number of options for the ...”
October 9, 2018
GMATGuruNY posted a reply to If x, y, and z are positive numbers, Is z between x and y? in the Data Sufficiency forum
“Statement 1: x < 2z < y Let x=2 and y=10. In this case: 2 < 2z < 10 1 < z < 5. If z=4, then it is between x=2 and y=10. If z=1.5, then it is not between x=2 and y=10. INSUFFICIENT. Statement 2: 2x < z < 2y Let x=2 and y=10. In this case: 2*2 < z ...”
October 9, 2018
GMATGuruNY posted a reply to If s is an integer between 0 and 10, is t less than the av in the Data Sufficiency forum
“The average of s and 10 lies HALFWAY between s and 10 on the number line: s------------AVERAGE------------10 Statement 1: Since t closer to 10 than to s, t must be greater than the average of s and 10, as shown here: s-----------AVERAGE---t----------10 Thus, the answer to the question stem is ...”
October 9, 2018
GMATGuruNY posted a reply to A group of 10 people consists of 3 married couples and 4 si in the Problem Solving forum
“Good committees = total committees - bad committees. Total committees: From 10 people, the number of ways to choose 4 = 10C4 = (10*9*8*7)/(4*3*2*1) = 210. Bad committees: Since a good committee includes at most 1 married couple, a bad committee is composed of 2 married couples. From 3 ...”
October 9, 2018
GMATGuruNY posted a reply to Problem solving: Difficulty level: 700, Source: Princeton in the Problem Solving forum
“For any evenly spaced set: sum = (number)(median) We can PLUG IN THE ANSWERS, which represent the sum. Since the number of integers can be 5 or 7, the sum must be a multiple of both 5 and 7. Eliminate A, which is not divisible by 5. Eliminate D, which is not divisible by 7. The equation in ...”
October 7, 2018
GMATGuruNY posted a reply to Health insurance Plan A requires the insured to pay $1000 or in the Problem Solving forum
“THE INSURED is the person covered by the insurance. Plan A: If $1000 is LESS than 50% of the cost level, then THE INSURED pays $1000, and PLAN A pays the remainder. If $1000 is MORE than 50% of the cost level, then THE INSURED pays 50% of the cost level, and PLAN A pays the remainder. Plan ...”
October 6, 2018
GMATGuruNY posted a reply to John tossed a fair coin 3 times. What is the probability in the Problem Solving forum
“P(TTH) = 1/2 * 1/2 * 1/2 = 1/8. Since H can occur on the 1st, 2nd or 3rd flip, we multiply by 3: 3*(1/8) = 3/8. The correct answer is C.”
October 6, 2018
GMATGuruNY posted a reply to Mixture Problem DS in the Data Sufficiency forum
“Yes -- each statement conveys the same information, since doubling the total volume is the equivalent of reducing the acid concentration by 1/2.”
October 6, 2018
GMATGuruNY posted a reply to The value of a share was 25% less in the 2nd quarter over in the Problem Solving forum
“Let the 1st-quarter value = 100. Since 2nd-quarter value is 25% less, the 2nd-quarter value = 100 - (25% of 100) = 100 - 25 = 75. Since the 3rd-quarter value is 20% more than the 2nd-quarter value, the 3rd-quarter value = 75 + (20% of 75) = 75 + 15 = 90. Since the 4th-quarter value must equal 120 ...”
October 6, 2018
GMATGuruNY posted a reply to Mixture Problem DS in the Data Sufficiency forum
“Statement 1 indicates that 80 grams of water are added to the 80 grams of original solution, DOUBLING the total volume from 80 grams to 160 grams Statement 2 indicates that the added water reduces the acid concentration by 1/2. Doubling the total volume will reduce the acid concentration by 1/2 ...”
October 6, 2018
GMATGuruNY posted a reply to Each year for 4 years, a farmer increased the number of in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the original number of trees. Since the number of trees increases by 1/4 each year, the correct answer must be a multiple of 4. The last 2 digits of a multiple of 4 must themselves form a multiple of 4. Eliminate A (1250) and C (2250), since 50 is ...”
October 5, 2018
ceilidh.erickson posted a reply to Advocates of a large-scale space-defense research project in the Critical Reasoning forum
“We''re asked for 4 answer choices that WEAKEN the conclusion. (Note: this does NOT mean to look for one answer that strengthens! It''s often the case that we''ll find 4 answers that weaken and one that''s irrelevant.) First, let''s determine where the argument is flawed: Premises: since ...”
October 5, 2018
ceilidh.erickson posted a reply to Guitar strings often go "dead"--become less respon in the Critical Reasoning forum
“When we''re asked what information would help us to EVALUATE an argument, we''re looking for a question for which a "yes" answer would weaken the argument and a "no" answer would strengthen the argument (or vice versa). Premise: Guitar strings often go "dead"--become ...”
October 5, 2018
GMATGuruNY posted a reply to A chessboard is an 8×8 array of identically sized squares. in the Problem Solving forum
“Case 1: Every 6-block rectangle with a base of 2 and a height of 3 yields 4 possible L-shapes: https://i.postimg.cc/1gJCfb5J/chessboard_L_shape_1.png Chessboard: https://i.postimg.cc/LYJThXW8/chessboard_whole.png The base for the 6-block rectangle shown above can appear in rows 1 through 6, ...”
October 5, 2018
GMATGuruNY posted a reply to Amit and Ian paint a wall in alternating shifts. First Amit in the Problem Solving forum
“During each of Amit''s 4 shifts, he paints 1/2 of the room, leaving 1/2 the room unpainted. Since 1/2 of the room is left unpainted FOUR TIMES, the total fraction left unpainted as a result of Amit''s 4 shifts = (1/2)⁴. Since Ian works after each of Amit''s first 3 shifts, Ian paints a total ...”
October 5, 2018
ceilidh.erickson posted a reply to A political candidate collected $1,749 from a fund raising in the Problem Solving forum
“If we want to MAXIMIZE the number of contributors, we must MINIMIZE the contributions of each person. We want as many people as possible to contribute exactly $50, so think of the greatest multiple of $50 that''s less than $1749. 34 people contributing exactly $50 would get us to $1700. Since we ...”
October 4, 2018
GMATGuruNY posted a reply to A thin piece of wire 40 meters long is cut into two pieces. in the Problem Solving forum
“Since the answer choices are in terms of a variable -- the value of r -- we can PLUG IN. Let the ENTIRE WIRE be used to form the square. Then: Perimeter of the square = 40. Side = 10. Area = 100. Circle area + square area = 0 + 100 = 100. This is our target. Since the circle has no ...”
October 4, 2018
GMATGuruNY posted a reply to If x and y are positive integers, is x^2*y^2 even ? in the Data Sufficiency forum
“x²y² will be even unless both x and y are ODD. Question stem, rephrased: Are x and y both odd? Statement 1: x+5 is prime number greater than 2 and thus must be ODD. Implication: x+5 = ODD x = ODD - 5 = ODD - ODD = EVEN. Since x is even, x and y cannot both be odd. SUFFICIENT. ...”
October 4, 2018
GMATGuruNY posted a reply to A hiker walking at a constant rate of 4 miles per hour is in the Problem Solving forum
“Rate and time have a RECIPROCAL RELATIONSHIP. The RATE RATIO for the hiker and cyclist = 4 mph : 20 mph = 1:5. Thus: The TIME RATIO for the hiker and cyclist = the reciprocal of the rate ratio = 5:1. Implication: The hiker will take 5 TIMES AS LONG as the cyclist to travel the same ...”
October 4, 2018
GMATGuruNY posted a reply to How many ounces of water must be added to 10 ounces of 3 % in the Problem Solving forum
“Alcohol percentage in the original solution: 3%. Alcohol percentage in the added water: 0%. Alcohol percentage in the mixture: 1%. 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: ...”
October 3, 2018
GMATGuruNY posted a reply to Vivian drives to her sister's house and back. She takes the in the Problem Solving forum
“When the same distance is traveled at two different speeds, the average speed for the entire trip will be a bit LESS than the average of the two speeds. Since (70+50)/2 = 60, the average speed for Vivian''s''s entire trip must be a bit less than 60. The correct answer is B.”
October 3, 2018
GMATGuruNY posted a reply to Tom’s Mom is five times as old as him. In 6 years, Tom’ in the Problem Solving forum
“An alternate approach is to PLUG IN THE ANSWERS, which represents Tom''s current age. When the correct answer is plugged in, Mom''s age in 6 years will be 3 times Tom''s age in 6 years. D: Tom = 6 Since Mom is currently 5 times as old as Tom, Mom = 5*6 = 30. Tom''s age in 6 years = 6+6 = 12. ...”
October 3, 2018
GMATGuruNY posted a reply to If 3 different numbers are selected from the first 8 prime n in the Problem Solving forum
“First 8 prime numbers: 2, 3, 5, 7, 11, 13, 17, 19. The sum will be even if 2 is among the three numbers selected, with the result that the sum = EVEN PRIME + ODD PRIME + ODD PRIME = EVEN. Since 3 NUMBERS are selected from 8 OPTIONS, the probability that 2 will be among the three numbers selected = ...”
October 2, 2018
GMATGuruNY posted a reply to In a certain office, 50 percent of the employees are college in the Data Sufficiency forum
“Let T = the total number of employees. Since 60% of the employees are over 40, we get: Over 40 = 0.6T 30% of those over 40 -- in other words, 30% of the expression in blue -- have master''s degrees. Thus: Over 40 with master''s = 0.3(0.6T). To calculate the value of the expression in ...”
October 2, 2018
GMATGuruNY posted a reply to On a 20 mile course, Pat bicycled at an average rate of 30 in the Problem Solving forum
“Since Pat travels at 30 miles per hour for the first 12 minutes -- the equivalent of 1/5 hour -- the distance traveled in the first 12 minutes = (30)(1/5) = 6 miles. Since the remaining 14 miles are traveled at 8 miles per hour, the time to travel the remaining 14 miles = 14/8 = 7/4 hours = 1 hour ...”
October 2, 2018
GMATGuruNY posted a reply to 190 students go to a school bake sale. 95 buy a chocolate in the Problem Solving forum
“Total = Group 1 + Group 2 - Both + Neither Here: Total = 190. Group 1 = 95 who buy chocolate chip. Group 2 = 75 who buy peanut butter. Plugging these values into the equation above, we get: 190 = 95 + 75 - Both + Neither 20 + Both = Neither Neither = 20 + Both. To minimize the value of ...”
October 2, 2018
GMATGuruNY posted a reply to Is x^3-x>0? in the Data Sufficiency forum
“Question stem, rephrased: Is x³ > x? Statement 1: x > 1 When a positive value greater than 1 is cubed, the result is greater than the original number: x=2 --> 2³ > 2 x=3 --> 3³ > 3 x=4 --> 4³ > 4 In every case, x³ > x. Thus, the answer to the rephrased ...”
October 2, 2018
GMATGuruNY posted a reply to The greatest common factor of 16 and the positive integer n in the Problem Solving forum
“The greatest common factor of 16 and the positive integer n is 4, and the greatest common factor of n and 45 is 3. Draw a VENN DIGRAM showing where the prime factors of n, 16 and 45 overlap: https://i.postimg.cc/xkyNCFg7/GCF_Venn_n_16_and_45.jpg The diagram implies the following: Since n and ...”
October 2, 2018
GMATGuruNY posted a reply to Five letters A, P, P, L and E are listed in a row. How many in the Problem Solving forum
“Good arrangements = total arrangements - bad arrangements. Total arrangements: Number of ways to arrange 5 elements = 5!. But when an arrangement includes IDENTICAL elements, we must divide by the number of ways each set of identical elements can be ARRANGED. The reason: When the ...”
October 1, 2018
GMATGuruNY posted a reply to If a, b, c, d, e are consecutive positive integers such that in the Problem Solving forum
“For any set of consecutive integers, average = median. Let the five integers = 1, 2, 3, 4, 5. Average of 2, 3, 4 and 5 = 3.5. Average of 1, 2, 3, and 4 = 2.5. Difference between the averages = 3.5 - 2.5 = 1. The correct answer is D.”
September 30, 2018
GMATGuruNY posted a reply to If a, b, c, d, e are integers such that a<b<c<d< in the Data Sufficiency forum
“Statement 1: For any set of consecutive integers, average = median. Case 1: 1, 2, 3, 4, 5 Average of 2, 3, 4 and 5 = 3.5. Average of 1, 2, 3, and 4 = 2.5. Difference between the averages = 3.5 - 2.5 = 1. Case 2: 2, 3, 4, 5, 6 Average of 3, 4, 5, and 6 = 4.5. Average of 2, 3, 4 and 5 = ...”
September 30, 2018
GMATGuruNY posted a reply to If x is the greatest common factor of 36 and 96, what is the in the Problem Solving forum
“36 = 2*2*3*3 96 = 2*2*2*2*2*3 GCF = the product of the factors in blue = 2*2*3 = 12. Sum of the digits = 1+2 = 3. The correct answer is B.”
September 30, 2018
GMATGuruNY posted a reply to Bob invested $2000 in fund A and $1000 in fund B. Over the in the Problem Solving forum
“Fund A after 2 years: 2000 + (10% of 2000) + (2)(1% of 2000) = 2000 + 200 + 2(20) = 2240. Fund B after 1 year: 1000 + (30% of 1000) = 1000 + 300 = 1300. Fund B after 2 years: 1300 + (30% of 1300) = 1300 + 390 = 1690. Difference after two years: 2240 - 1690 = 550. The correct answer is ...”
September 30, 2018
GMATGuruNY posted a reply to If a photocopier makes 2 copies in 1313 second, then, at the in the Problem Solving forum
“Using ratios, convert 4 minutes into copies: (4 minutes) * (60 seconds)/(1 minute) * (2 copies)/(1/3 second) = 1440 copies. The correct answer is E.”
September 30, 2018
GMATGuruNY posted a reply to Lindsay can paint 1/x of a certain room in 20 minutes. What in the Problem Solving forum
“Let the room = 20 units. Let x = 4. Since Lindsay paints 1/x of the room in 20 minutes -- the equivalent of 1/3 hour -- Lindsay''s rate = (1/4) * 20 = 5 units per 1/3 hour = 15 units per hour. Since Lindsay and Joseph paint the entire room in 1 hour, their combined rate = 20 units per hour. ...”
September 29, 2018
GMATGuruNY posted a reply to 50% of students' study science and 30% of science students in the Problem Solving forum
“Let the total number of students = 100. Since 50% of the students study science, the number of science students = (50/100)(100) = 50, implying that the number of non-science students = 100-50 = 50. Since 30% of the 50 science students score more than 80%, the number of science students who ...”
September 29, 2018
GMATGuruNY posted a reply to A garden center sells a certain grass seed in 5-pound bags in the Problem Solving forum
“5-pound bags = ($13.85)/5 ≈ $3 per pound. 10-pound bags = ($20.43)/10 = more than $2 per pound. 25-pound bags = ($32.25)/25 = less than $1.50 per pound. To minimize the cost, we must maximize the number of 25-pound bags, which offer seed at the lowest price per pound. Two 25-pound bags = 50 ...”
September 29, 2018
GMATGuruNY posted a reply to Which of the following equations is NOT equivalent to in the Problem Solving forum
“If we plug y=-3 into 4x² = y²-9, we get: 4x² = (-3)² - 9 4x² = 0 x = 0. Test x=0 and y=-3 in the answer choices. When the question stem includes the phrase which of the following, the correct answer is likely to be D or E. D: 2x = y-3 Plugging in x=0 and y=-3, we get: 2*0 = -3-3 0 = ...”
September 28, 2018
GMATGuruNY posted a reply to If non- negative integers n & p are not both odd, in the Problem Solving forum
“If n=p=0, options A, B, C and D each yield a even value, indicating that these options do NOT have to be odd. Eliminate A, B, C and D. The correct answer is E.”
September 28, 2018
GMATGuruNY posted a reply to Is |x+y|<|x|+|y|? in the Data Sufficiency forum
“Since an absolute value cannot be negative, both sides of the question stem are NONNEGATIVE, enabling us to safely square the inequality: (|x+y|)²< (|x|+|y|)² x² + y² + 2xy < x² + y² + 2|x||y| xy < |xy| The resulting inequality is valid only if x and y have DIFFERENT SIGNS. ...”
September 28, 2018
GMATGuruNY posted a reply to The shaded portion of the rectangular lot shown above in the Problem Solving forum
“ALWAYS KEEP YOUR EYES ON THE ANSWER CHOICES. C, D and E imply that the flower bed is probably a 6-8-10 triangle in which y=6, x = y+2 = 6+2 = 8, and z=10. Check whether this triangle satisfies the condition that the flower bed has an area of 24 square yards: Area of a 6-8-10 triangle = ...”
September 27, 2018
GMATGuruNY posted a reply to Anna wants to distribute chocolates among her four children in the Problem Solving forum
“Let the total number of chocolates = the LCM of the four denominators 2, 5, 6 and 12 = 60. Number of chocolates given to the four children: (1/2)(60) = 30 (1/5)(60) = 12 (1/6)(60) = 10 (1/12)(60) = 5 Total number of chocolates = 30+12+10+5 = 57. The correct answer is C.”
September 27, 2018
GMATGuruNY posted a reply to In 2004, 2,400 condos sold, 15% of the total housing units in the Problem Solving forum
“Of the units sold, non-condos constitute 85% = 85/100 = 17/20. Implication: Of every 20 units sold, 17 are non-condos, with the result that the number of non-condos must be a multiple of 17. A. 16000 B. 13600 C. 12400 D. 11200 E. 8600 Only the portion in green is a multiple of 17: ...”
September 27, 2018
GMATGuruNY posted a reply to If the probability of Ronaldo will score at least 3 goals in in the Problem Solving forum
“Let G = at least 3 goals and NG = not at least 3 goals. Let W = win the match and NW = not win the match. Use a DOUBLE-MATRIX to organize the data: https://i.postimg.cc/JHLj6Tyr/matrix_goals_wins_0.png The probability that Ronaldo will score at least 3 goals in the match is 0.59. The ...”
September 27, 2018
ceilidh.erickson posted a reply to If z is a multiple of 9 and w is a multiple of 4, is zw a in the Data Sufficiency forum
“Btw, this question is nearly identical to this OG question: https://www.beatthegmat.com/is-xy-a-multiple-of-105-t274522.html#712134”
September 27, 2018
ceilidh.erickson posted a reply to If z is a multiple of 9 and w is a multiple of 4, is zw a in the Data Sufficiency forum
“First, REPHRASE the given information: - if z is a multiple of 9, it contains two factors of 3. - if w is a multiple of 4, it contains two factors of 2. - the product zw must contain two factors of 2 and two factors of 3. Now rephrase the question: Is zw a multiple of 126 --> does zw ...”
September 27, 2018
ceilidh.erickson posted a reply to Time for me to Stop Studying on my Own? - GMAT Quant Help in the GMAT Math forum
“You said that you got a 38-V, 38-Q on your 1st CAT. That would track to a 630, not a 500: https://www.manhattanprep.com/gmat/gmat-score-calculator/ I assume that you mean percentiles. IGNORE YOUR PERCENTILES! They are misleading: ...”
September 26, 2018
GMATGuruNY posted a reply to A set of numbers has an average of 50. If the largest elemen in the Problem Solving forum
“Let S = the smallest number of L = the largest number. Since the largest number is 4 more than 3 times the smallest number, we get: L = 3S + 4 L-4 = 3S (L-4)/3 = S. Since the average is 50 -- and the numbers are not all the same -- S must be LESS THAN 50, while L must be greater than 50. ...”
September 26, 2018
GMATGuruNY posted a reply to What is the sum of the solutions of the equation (x-1)^2=|x- in the Problem Solving forum
“If we replace x-1 with a, we get: a² = |a|. The resulting equation is valid only if a -- in other words, the value of x-1 -- is equal to -1, 0, or 1: x-1 = -1 --> x=0 x-1 = 0 ---> x=1 x-1 = 1 ---> x=2 Sum of the solutions = 0+1+2 = 3. The correct answer is E.”
September 26, 2018
GMATGuruNY posted a reply to If H = [(x^3) - 6(x^2) - x + 30] / (x-5)and x ≠ 5, then H in the Problem Solving forum
“Let x=0, with the result that H = 30/-5 = -6. Now plug x=0 in the answers to see which yields a value of -6. Only A works: x² - x - 6 = 0² - 0 - 6 = -6. The correct answer is A.”
September 26, 2018
GMATGuruNY posted a reply to Robin split a total of $24,000 between 2 investments, X and in the Data Sufficiency forum
“Statement 1: Test one case that also satisfies Statement 2. Case 1: X = 5% and Y = 7% For 5% interest and 7% percent interest to yield the same dollar amount, $7 must be invested at 5% interest for every $5 invested at 7% interest: X --> $7(0.05) = $0.35. Y --> $5(0.07) = $0.35. Thus: ...”
September 25, 2018
GMATGuruNY posted a reply to In how many ways four men, two women and one child can sit a in the Problem Solving forum
“Once the child has been placed at the table: Number of ways to arrange the 2 women in the 2 seats adjacent to the child = 2! = 2. Number of ways to arrange the 4 men in the remaining 4 seats = 4! = 24. To combine these options, we multiply: 2*24 = 48. The correct answer is C.”
September 24, 2018
GMATGuruNY posted a reply to W, X, Y and Z each represent a different number. If the sum 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.”
September 24, 2018
GMATGuruNY posted a reply to How many 3 digit numbers can we make such that two of the in the Problem Solving forum
“Number of digit options for the repeated digit = 9. (Any digit but 0.) Number of digit options for the non-repeated digit = 8. (Any digit but 0 and the digit already used.) Number of position options for the non-repeated digit = 3. (The hundreds place, the tens place, or the units place.) To ...”
September 24, 2018
GMATGuruNY posted a reply to Is 10m > 5n - k? in the Data Sufficiency forum
“Statement 1: n=2m Substituting n=2m into 10m > 5n-k, we get: 10m > 5(2m) - k ? 10m > 10m - k ? 0 > -k ? k > 0 ? No way to determine whether k>0. INSUFFICIENT. Statement 2: |k| = -k This equation is valid only if k≤0. No information about m or n. INSUFFICIENT. ...”
September 23, 2018
GMATGuruNY posted a reply to Machine A and Machine B can produce 1 widget in 3 hours work in the Problem Solving forum
“Algebra: Machine A and Machine B can produce 1 widget in 3 hours working together at their respective constant rates. (A+B)(3) = 1 widget. If Machine A''s speed were doubled, the two machines could produce 1 widget in 2 hours working together at their respective rates. (2A+B)(2) = 1 widget. ...”
September 23, 2018
GMATGuruNY posted a reply to Machine A and Machine B can produce 1 widget in 3 hours work in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent A''s time to produce 1 widget. Since A and B working together take 3 hours to produce 1 widget, A working alone must take MORE than 3 hours. Eliminate A, B and C. Let the value of each widget = 30 units. Since A and B together take 3 hours to produce ...”
September 23, 2018
GMATGuruNY posted a reply to In an office that employs 120 people, m% of the employees in the Data Sufficiency forum
“Use a DOUBLE-MATRIX to organize the data. Statements combined: Case 1: m=25% and c=25% Total number of males = (25/100)(120) = 30. Total number of custodial employees = (25/100)(120) = 30. The following matrix is yielded: https://i.postimg.cc/H88Lq5zN/matrix_custodial_1.png In this case, ...”
September 22, 2018
ceilidh.erickson posted a reply to Best Way to Study with GMAT Books Already Purchased? in the GMAT Strategy forum
“No, I''m afraid this is not a good plan. There are several problems: - there is absolutely no way that you can get a 750 by focusing on quant alone. You have to maximize both quant and verbal. See the score calculator here: https://www.manhattanprep.com/gmat/gmat-score-calculator/ - you''re ...”
September 21, 2018
ceilidh.erickson posted a reply to Taking the GMAT in four days. Need advice calming my nerves in the GMAT Strategy forum
“CONGRATULATIONS!!! That''s a fantastic score! I always tell my students to take the exam twice. With all the time and money you''re planning to invest in graduate school, why not invest another day of your time + $250 to maximize your score? There''s always a margin of error of +/- 20 pts or so, ...”
September 21, 2018
ceilidh.erickson posted a reply to If m > 0, y > 0, and x is m percent of 2y, then, in te in the Problem Solving forum
“Here''s another similar problem to try, both algebraically and with plugging numbers: https://www.beatthegmat.com/if-m-0-and-x-is-t68852.html#800983”
September 21, 2018
ceilidh.erickson posted a reply to If m > 0, y > 0, and x is m percent of 2y, then, in te in the Problem Solving forum
“Here''s another way to set it up algebraically: x is m percent of 2y ---> \E.”
September 21, 2018
ceilidh.erickson posted a reply to Because of a rare type of fungus that killed off many cacao in the Critical Reasoning forum
“When we''re asked to EVALUATE an argument, we must first determine how the argument is logically flawed. Premises: - Because of a rare type of fungus that killed off many cacao trees in Brazil, there was an unusually meager harvest of cacao beans this year. - The wholesale price of cocoa ...”
September 21, 2018
ceilidh.erickson posted a reply to With its plan to develop seven and a half acres of shore in the Sentence Correction forum
“Because the dependent clause beginning with "that" is modifying "a large number of communities," the verb should be PLURAL. Remember that in English, certain expressions with prepositions are considered plural: - some of the people are... - all of the ducks have... - many of ...”
September 21, 2018
ceilidh.erickson posted a reply to When there is less rainfall than normal, the water level of in the Critical Reasoning forum
“When you have a CR problem that asks you to EXPLAIN A DISCREPANCY, it''s usually in this format: - It''s generally true that ______. - Normally, you''d think this would mean ______. - In this case, though, _______. We need to find an answer that 1) keeps the original conditions true, ...”
September 21, 2018
ceilidh.erickson posted a reply to The proportion of women among students enrolled in higher in the Critical Reasoning forum
“In order to EVALUATE an argument, we must first find the logical flaw in the argument. This argument is conflating two different metrics: 1. the proportion of women among total students: (women students)/(women students + non-women students) 2. the proportion of all women of a certain age who ...”
September 21, 2018
GMATGuruNY posted a reply to In these difficult economic times, those who have---Veriats in the Sentence Correction forum
“The default referent for a subject pronoun is the subject of the preceding INDEPENDENT CLAUSE. A: Those who have public pensions are being pursued strongly by pension advance companies that operate without much oversight from banking regulators, but they are now drawing scrutiny. Here, the default ...”
September 21, 2018
GMATGuruNY posted a reply to GMATPREP Question - what is the subject in the Sentence Correction forum
“This interpretation is not valid. The comparative in blue is clearly an ADJECTIVE describing a city.. Since as big as refers not to China but to A CITY. no comparison between China and Singapore is implied. The sentence unambiguously compares A CITY to Singapore, as discussed below. ...”
September 21, 2018
GMATGuruNY posted a reply to If m > 0, y > 0, and x is m percent of 2y, then, in te in the Problem Solving forum
“Let y=100, implying that 2y = 200. Let m=100. x is m percent of 2y. Since m=100 and 2y=200, x = 100% of 200 = 200. m is what percent of x? m/x = 100/200 = 1/2 = 50%. This is our target. Now plug y=100 into the answers to see which yields the target value of 50. Only E works: 5000/y = ...”
September 21, 2018
GMATGuruNY posted a reply to If 7 < m < 11 and −2 < n < 5, then which of th in the Problem Solving forum
“To determine the lower limit and the upper limit of mn, calculate mn using every combination of endpoints (7 and 11 for m, -2 and 5 for n): mn = (7)(-2) = -14. mn = (7)(5) = 35. mn = (11)(-2) = -22. mn = (11)(5) = 55. The LOWER limit is the LEAST of the results above: -22. The UPPER ...”
September 21, 2018
GMATGuruNY posted a reply to The square ACEG shown below has an area of 36 units squared. in the Problem Solving forum
“Almost no math is needed here. Answer choice A implies the following: BCD is a 45-45-90 triangle in which each leg has a length of 1. DEF is a 45-45-90 triangle in which each leg has a length of 5. Answer choice E implies the following: BCD is a 45-45-90 triangle in which each leg has a ...”
September 20, 2018
GMATGuruNY posted a reply to If Albert can travel 200 miles in 4 hours, how many hours in the Problem Solving forum
“Since Albert travels 200 miles in 4 hours, his rate = 200/4 = 50 mph. When the correct answer is divided into 350 miles, the resulting rate must be 50 mph. Only C works: 350/7 = 50. The correct answer is C.”
September 20, 2018
GMATGuruNY posted a reply to In four years, Andy will be twice as old as Betsy. How old in the Data Sufficiency forum
“In four years, Andy will be twice as old as Betsy. Since Andy''s age in 4 years is twice Betsy''s age in 4 years, we get: A+4 = 2(B+4) A+4 = 2B+8 A-2B = 4. Statement 1: Since Andy''s age 4 years ago is twice Betsy''s current age, we get: A-4 = 2B A-2B = 4. Same equation as given in the ...”
September 20, 2018
GMATGuruNY posted a reply to How many multiples of 33 lie between 101 and 1,000, inclusiv in the Problem Solving forum
“Since 1000 - 101 ≈ 900 -- and the answer choices are a bit spread out -- we can count the multiples of 33 simply by dividing 33 into 900: 900/33 = 300/11 = a bit more than 27. Thus, there are 27 multiples of 33 between 101 and 1000. The correct answer is B.”
September 20, 2018
GMATGuruNY posted a reply to Comparison - GMAT paper test in the Sentence Correction forum
“OA: A neutron star, as small as 12 miles in diameter but containing half as much matter as the Sun, has a gravitational force at its surface about 67 billion times greater than that on Earth. The green portion conveys the following meaning: The words in brackets are omitted so that the green ...”
September 19, 2018
GMATGuruNY posted a reply to Rasheed bought two kinds of candy bars, chocolate and toffee in the Data Sufficiency forum
“I believe that the problem has been transcribed incorrectly. Statement 1 should indicate that Rasheed bought not 2 fewer packages but only 1 fewer package, as shown in the following screen shot: https://i.postimg.cc/t7bcm77Z/rasheed_Gprep-ds-2.jpg If we know the number of chocolate BARS that ...”
September 19, 2018
GMATGuruNY posted a reply to √3-2|+|3-√2|+|5+√3|+|1-√2|=? in the Problem Solving forum
“|a-b| = the distance between a and b. |a+b| = |a-(-b| = the distance between a and -b. |√3-2| + |3-√2| + |5+√3| + |1-√2| = |5+√3| + |√3-2| + |1-√2| + |3-√2| = |√3+5| + |√3-2| + |1-√2| + |3-√2| = |√3-(-5)| + |√3-2| + |1-√2| + |3-√2| The red terms ...”
September 19, 2018
GMATGuruNY posted a reply to On the number line shown, the distance between 0 and a, a in the Problem Solving forum
“In the number line shown, the distance between 0 and a, a and b, and a and c is in the ratio of 1:2:3. To determine the ratio of a to b to c, TEST AN EASY CASE. Let a=1. Since a is ONE PLACE to the right of 0, b must be TWO PLACES to the right of a (implying that b=3), while c must be THREE ...”
September 18, 2018
GMATGuruNY posted a reply to If 12 men and 16 women can do a piece of work in 5 days and in the Problem Solving forum
“Let M = the rate for each man and W = the rate for each woman. The TIME RATIO for 12 men and 16 women to 13 men and 24 women is 5 days to 4 days. Since time and rate are RECIPROCALS, the RATE RATIO for 12M+16W and 13M+24W is equal to the reciprocal of the time ratio: (12M+16W)/(13M+24W) = ...”
September 18, 2018
GMATGuruNY posted a reply to A certain investment grows at an annual interest rate of 8%, in the Problem Solving forum
“When a value increases repeatedly by r%: Final amount = Original amount * (1 + r/100)^number of changes. Let original amount = 1. Since the original amount increases by a factor of 16: Final amount = 16. Since the investment increases by 2% every quarter: r = 2. Since x = the number of ...”
September 18, 2018
GMATGuruNY posted a reply to Grandmother's Punch hangover cure is a mix of two in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the amount of cider. When the correct answer is plugged in, the amount of alcohol in the 750 ml bottle = 87 ml. Since the alcohol percentage in the cider = 5% = 1/20, the correct answer is almost certain to be a multiple of 20. Of the five answer ...”
September 17, 2018
GMATGuruNY posted a reply to A tank has 5 inlet pipes. Three pipes are narrow and two are in the Problem Solving forum
“Let the rate of each wide pipe = 2 liters per hour. Combined rate for 2 wide pipes = 2*2 = 4 liters per hour. Since each narrow pipe works at 1/2 the rate of each wide pipe, the rate of each narrow pipe = (1/2)(2) = 1 liter per hour. Combined rate for 3 narrow pipes and 2 wide pipes = (3*1) + ...”
September 16, 2018
GMATGuruNY posted a reply to Gunther, the pizza delivery boy, went out from the store in the Problem Solving forum
“Average = sum/quantity. In this case: Average speed = (sum of the minutes spent at each speed)/(total number of minutes). Total time spent at 15mph = 30 minutes. Total time spent delivering pizzas at 0mph = 30 minutes. Total time spent at 30mph = 15 minutes. Average speed = (15*30 + 0*30 + ...”
September 15, 2018
GMATGuruNY posted a reply to A basket contains 5 apples, of which 1 is spoiled and the in the Problem Solving forum
“P(spoiled apple is selected) = 1 - P(spoiled apple is NOT selected). P(1st apple is not spoiled) = 4/5. (Of the 5 apples, 4 are not spoiled). P(2nd apple is not spoiled) = 3/4. (Of the 4 remaining apples, 3 are not spoiled). Since we want both events to happen, we multiply the fractions: ...”
September 15, 2018
GMATGuruNY posted a reply to Point P is the point of the circle x^2 + y^2 -2x -4y = 4 wit in the Problem Solving forum
“(x-h)² + (y-k)² = r² is a circle with a center at (h, k) and a radius of r. x² + y² - 2x - 4y = 4 x² - 2x + y² - 4y = 4 x² - 2x + 1 + y² - 4y + 4 = 4 + 1 + 4 (x-1)² + (y-2)² = 9 (x-1)² + (y-2)² = 3³ The equation above constitutes a circle with a center at (1, 2) and a ...”
September 14, 2018
ceilidh.erickson posted a reply to Scoring Verbal 45+ in the GMAT Verbal & Essays forum
“There''s no special strategy for scoring a 45+ verbal that''s any different from what everyone should do to maximize their scores: - Read strategy guides to make sure you''re using good process, and not just relying on instincts. More here: ...”
September 14, 2018
ceilidh.erickson posted a reply to Taking the GMAT in four days. Need advice calming my nerves in the GMAT Strategy forum
“Here are some other resources to help combat / reframe anxiety: http://www.ted.com/talks/kelly_mcgonigal_how_to_make_stress_your_friend?language=en https://www.manhattanprep.com/gmat/blog/2013/05/09/stressed-out-meditate-to-lower-your-anxiety-and-boost-your-gmat-score/ ...”
September 14, 2018
ceilidh.erickson posted a reply to Taking the GMAT in four days. Need advice calming my nerves in the GMAT Strategy forum
“I definitely agree with what Rich said. Here are a few other pieces of advice: - Tell yourself that no matter what, you''ll take it a 2nd time. There''s always a margin of error of +/- 20pts, so even if you have a great test day and get a 720, why not roll the dice again and see if you can get a ...”
September 14, 2018
GMATGuruNY posted a reply to At what speed was Erik running when he was at the halfway in the Data Sufficiency forum
“Statements combined: Each statement conveys the same information: that the average speed for the whole trip was 5 miles per hour. The AVERAGE speed for the whole trip does not constrain the speed AT THE HALWAY POINT. At the halfway point, the speed could be ANY NONNEGATIVE VALUE. Thus, the ...”
September 13, 2018
GMATGuruNY posted a reply to (1^2+2^2+3^3+…+20^2) / (1+2+3+ …+20)=? in the Problem Solving forum
“The answer choices represent the ratio between the numerator and the denominator of the given expression. Option A implies that the numerator is about 14 times the denominator Option B implies that the numerator is less than 7 times the denominator. Option C implies that the numerator is 41 times ...”
September 13, 2018
GMATGuruNY posted a reply to (1^2+2^2+3^3+…+20^2) / (1+2+3+ …+20)=? in the Problem Solving forum
“Since the answer choices are very spread out, we can BALLPARK -- and we can be somewhat lax with our estimations. Numerator: If the 11 greatest terms were 10²=100, the sum of the 11 greatest terms = 11*100 = 1100. If the 11 greatest terms were 20²=400, the sum of the 11 greatest terms = ...”
September 13, 2018
GMATGuruNY posted a reply to If the interior angles of a triangle are in the ratio 3 to in the Problem Solving forum
“The sum of the 3 angles of a triangle = 180. The sum of the parts of the ratio = 3+4+5 = 12. Since 180/12 = 15, the multiplier for the ratio is 15, implying that the largest angle = 5*15 = 75. The correct answer is D.”
September 12, 2018
GMATGuruNY posted a reply to During a one day sale, a store sold each sweater of a in the Data Sufficiency forum
“Statement 1: Case 1: 1 sweater is sold for $270 Case 2: 3 sweaters are sold for $90 each Since the number of sweaters sold can be different values, INSUFFICIENT. Statement 2: Since the $30 markup is 1/2 the cost of each sweater, the cost of each sweater = 60. Thus, the selling price of ...”
September 12, 2018
GMATGuruNY posted a reply to Three boys are ages 4, 6 and 7 respectively. Three girls are in the Problem Solving forum
“Since only a few cases are possible, we can list them out: 4+6+5+8 = 23 4+6+5+9 = 24 4+6+8+9 = 27 4+7+5+8 = 24 4+7+5+9 = 25 4+7+8+9 = 28 6+7+5+8 = 26 6+7+5+9 = 27 6+7+8+9 = 30 Of the 9 cases above, the four in red are ODD, implying that the remaining five cases are EVEN. Since 5/9 of ...”
September 12, 2018
GMATGuruNY posted a reply to The perimeter of a rectangular garden is 360 ft. What is the in the Data Sufficiency forum
“The GRE is administered by ETS, which also used to administer the GMAT. The GRE Quantitative Guide states that any side of a triangle or parallelogram can be used as a base. The GMAT is likely to abide by this definition. But the terms length and long seem to connote a different meaning when ...”
September 11, 2018
GMATGuruNY posted a reply to The perimeter of a rectangular garden is 360 ft. What is the in the Data Sufficiency forum
“Definitions of length: Merriam-Webster: The LONGER OR LONGEST dimension of an object. American Heritage: The measurement of something along its GREATEST dimension.”
September 11, 2018
GMATGuruNY posted a reply to a family has 5 children, what is the probability that there in the Problem Solving forum
“The problem should make clear that P(boy) = P(girl) = 1/2: P(exactly n times) = P(one way) * total possible ways. Let B = boy and G = girl. P(one way): One way to get exactly 3 boys and 2 girls is BBBGG. P(BBBGG) = 1/2 * 1/2 * 1/2 * 1/2 * 1/2 = 1/32. Total possible ways: Any ...”
September 11, 2018
GMATGuruNY posted a reply to The sum of the ages of Doris and Fred is y years. If Doris in the Problem Solving forum
“Since Doris is 12 years older than Fred, let Fred = 2 and Doris = 2+12 = 14. y = sum of their ages = 2+14 = 16. Since Fred = 2 and y=16, Fred''s age y years from now = 2+16 = 18. This is our target. Now plug y=16 into the answers to see which yields the target value of 18. Only D works: 3y/2 - ...”
September 11, 2018
ceilidh.erickson posted a reply to Any decimal that has only a finite number of nonzero digits in the Data Sufficiency forum
“Here is further explanation on the logic of terminating decimals: https://www.beatthegmat.com/ds-decimals-and-ratio-combined-t182983.html#583298”
September 10, 2018
ceilidh.erickson posted a reply to A certain ice cream factory makes two flavors of ice cream: in the Data Sufficiency forum
“This question is faulty as written. We''re told: Then statement 1 says: If the only 2 varieties are over or under 20%, then it should be the case that if 80% is over 10% milk, the other 20% is under 10% milk, and this is the entire category of under-20%-milk. Instead, this implies that ...”
September 10, 2018
ceilidh.erickson posted a reply to Four men and three women make up a seven-member committee. in the Data Sufficiency forum
“For more examples of "when you see ''at least'', think of the opposite," see: https://www.beatthegmat.com/can-someone-please-give-me-the-reasoning-to-this-ds-problem-t32360.html https://www.beatthegmat.com/jury-selection-probability-t270645.html#698357 ...”
September 10, 2018
ceilidh.erickson posted a reply to Four men and three women make up a seven-member committee. in the Data Sufficiency forum
“Here''s a good general rule: whenever you see "AT LEAST" in a DS question, it helps to think: "when would that NOT be the case?" This question asks "does at least one man sit next to another man?" There are lots of ways to picture this happening, so how would it NOT ...”
September 10, 2018
ceilidh.erickson posted a reply to K is a rectangular solid. Find the volume of K in the Data Sufficiency forum
“You can easily test values to prove insufficiency. (1) a diagonal line across the front face of K has a length of 40 This give us limited information about 2 of our dimensions, but nothing about the 3rd. It''s easy to imagine 40 as the hypotenuse of a 3 : 4 : 5 triangle, so we can imagine ...”
September 10, 2018
ceilidh.erickson posted a reply to Bluegrass musician Bill Monroe, whose repertory, views on in the Sentence Correction forum
“This question is testing SUBJECT/VERB agreement, IDIOMS, and CONCISION. (A) were influential on generations of bluegrass artists, was also an inspiration to many musicians, that included Elvis Presley and Jerry Garcia, whose music differed significantly from - "that included" is not ...”
September 10, 2018
GMATGuruNY posted a reply to The rate of a certain chemical reaction is directly in the Problem Solving forum
“The trick is translate the chemical relationship into the following equation: R = A²/B Here''s why the equation above works: 1)The problem states that R is directly proportional to A². Directly proportional means that as one value increases, the other value also increases by a ...”
September 10, 2018
GMATGuruNY posted a reply to In a certain pond, 50 fish were caught, tagged, and returned in the Problem Solving forum
“Of the 50 fish caught in the second catch, 2 were tagged: 2/50 = 4/100 = 4%. Since the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond, the total number of tagged fish -- 50 -- must be equal to about 4% of the total number of fish in the pond: 50 = ...”
September 10, 2018
GMATGuruNY posted a reply to If 5^{m-2}2^{m+2} is an n-digit integer, where m is an inte in the Problem Solving forum
“Since m=2 will yield an integer value for the given expression and will make the math easier, ignore the condition that m>2 and let m=2. Plugging m=2 into 5^(m-2) * 2^(m+2), we get: 5⁰2⁴ = 1*16 = 16. Since the result is a 2-digit integer, n=2. The correct answer must work for n=m=2. Only ...”
September 10, 2018
GMATGuruNY posted a reply to Sam's car was fined when he gave Joe and Peter a ride, so in the Problem Solving forum
“Thanks for the heads up. I''ve revised my post accordingly.”
September 9, 2018
GMATGuruNY posted a reply to What is the probability of n(n+1)(n+2) being evenly divisibl in the Data Sufficiency forum
“Statement 1: Since n is an integer, n(n+1)(n+2) = the product of 3 consecutive integers. WRITE IT OUT and LOOK FOR A PATTERN. 1*2*3 2*3*4 3*4*5 4*5*6 5*6*7 6*7*8 7*8*9 8*9*10 9*10*11 10*11*12 11*12*13 12*13*14 13*14*15 14*15*16 15*16*17 16*17*18 Each of the products in red ...”
September 9, 2018
GMATGuruNY posted a reply to Twenty-four men can complete a work in sixteen days.Thirty in the Problem Solving forum
“Let the rate for each man = 1 widget per day, implying that the rate for 24 men = 24 widgets per day. Since 24 men complete the job in 16 days, the total amount of work = rt = 24*16 widgets. Since 32 women require 24 days, the rate for 32 women = w/t = (24*16)/24 = 16 widgets per day. Since ...”
September 9, 2018
GMATGuruNY posted a reply to Sam's car was fined when he gave Joe and Peter a ride, so in the Problem Solving forum
“Given that the answers choices are integers, I believe that the following reflects the problem''s intent: The three fractions in the prompt -- 1/4, 1/3 and 1/2 -- imply that the fine must be divisible by 4, 3 and 2. Smallest possible case: Total fine = 4*3*2 = 24. Since Sam paid $4 less ...”
September 9, 2018
GMATGuruNY posted a reply to GMATPREP Question - what is the subject in the Sentence Correction forum
“Option B for SC18 in the OG12: Plants are more efficient at acquiring carbon than fungi. Logical interpretation 1: Plants are more efficient at acquiring carbon than Logical interpretation 2: Plants are more efficient at acquiring carbon than fungi Since B allows for more than one logical ...”
September 8, 2018
GMATGuruNY posted a reply to The bear alarm at Grizzly's Peak ski resort sounds an in the Problem Solving forum
“The alarm sounds for 3 of EVERY 4 BEARS that actually appear, If 4 bears appear, then the number of alarms = 3. Since the alarm sounds only 3 times for 4 bears, 1 of these 4 bears is undetected. Since there are 10 false alarms for every 1 undetected bear, the number of false alarms = 10. Thus, ...”
September 7, 2018
GMATGuruNY posted a reply to If a mixture of ground meat consists of 2 pounds of veal in the Problem Solving forum
“The answer choices represent the price per pound: (total cost)/(total number of pounds). Since 7 pounds are purchased, the correct answer must have a denominator of 7. A, C and D lack denominators and thus can be eliminated. Since the denominator in B does not have to be 7, eliminate B. The ...”
September 7, 2018
GMATGuruNY posted a reply to How many hours did it take Dale to drive from A-town to B-to in the Data Sufficiency forum
“Statement 1: Time and rate have a RECIPROCAL relationship. 3 TIMES AS FAST implies 1/3 THE TIME. Thus, the 2 hours that would be spent traveling 3 times as fast must be equal to 1/3 the actual time: 2 = (1/3)t t = 6 hours. SUFFICIENT. Statement 2: Here, the time can be any nonnegative ...”
September 7, 2018
GMATGuruNY posted a reply to A palindrome is a number that reads the same forward and in the Problem Solving forum
“Number of options for the units digit = 5. (1, 3, 5, 7, or 9.) Number of options for the thousands digit = 1. (Must be the same as the units digit.) Number of options for the hundreds digit = 10. (Any of the digits 0-9.) Number of options for the tens digit = 1. (Must be the same as the hundreds ...”
September 7, 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)(1) = 3. Since the earnings increase by m=100%, the new earnings = ...”
September 6, 2018
GMATGuruNY posted a reply to What is the sum of roots of the equation x^2 – 40x + 399 = in the Problem Solving forum
“For any quadratic in the form x² + bx + c = 0: Sum of the roots = -b. Product of the roots = c. In the given quadratic, b = -40. Thus, the sum of the roots = -b = -(-40) = 40. The correct answer is D.”
September 6, 2018
GMATGuruNY posted a reply to If 3x + 2y = -2z, what is x? in the Data Sufficiency forum
“Prompt: 3x + 2y + 2z = 0 Statement 1: Multiplying by 2, we get: 2x - 2y - 2z = 20 Adding together 3x+2y+2z=0 and 2x-2y-2z=20, we get: (3x+2y+2z) + (2x-2y-2z) = 0 + 20 5x=20 x=4. SUFFICIENT. Statement 2: Multiplying by 2, we get: 2x + 2y + 2z = -4 Subtracting 2x+2y+2z = -4 from ...”
September 6, 2018
GMATGuruNY posted a reply to A and B can complete a task in 20 days. B and C can complete in the Problem Solving forum
“Alternate approach: Let the job = 240 units. Since A+B take 20 days to complete the 240-unit job, A+B = 240/20 = 12 units per day. Since B+C take 30 days to complete the 240-unit job, B+C = 240/30 = 8 units per day. Since A+C take 40 days to complete the 240-unit job, A+C = 240/40 = 6 units ...”
September 6, 2018
ceilidh.erickson posted a reply to I cud beat the GMAT: from 680(50,32) to 740(50,40)[97%] in the I just Beat The GMAT! forum
“First of all - CONGRATULATIONS!! That''s a fantastic score, and I hope you''re gotten into fantastic schools. Secondly, this is such a helpful and thorough breakdown - I''m sure others have found it very helpful. Thirdly, I''m so glad that you found the Manhattan Prep GMAT materials helpful!”
September 5, 2018
ceilidh.erickson posted a reply to An assumption question - salt cause high blood pressure, in the Critical Reasoning forum
“I see what you mean here. One way to read it is "1. THESE facts don''t establish salt as the culprit, but some OTHER facts might establish salt as the culprit" rather than "2. these facts do not suggest SALT as the culprit, because there is some other culprit." I think both of ...”
September 5, 2018
ceilidh.erickson posted a reply to GMATPrep: The number of applications for teaching in the Critical Reasoning forum
“For more on using this process for DISCREPANCY problems, see: https://www.beatthegmat.com/erythrovirus412-t289423.html#767088 https://www.beatthegmat.com/critical-reasoning-t278017.html#725224 https://www.beatthegmat.com/resolve-the-paradox-t275859.html#717366 ...”
September 5, 2018
ceilidh.erickson posted a reply to GMATPrep: The number of applications for teaching in the Critical Reasoning forum
“I''m happy to help! Here is the general process you should use for EXPLAIN DISCREPANCY problems: 1. Evaluate the given circumstance / phenomenon. 2. Think about what you would have expected / what the normal outcome would likely have been (this is usually unstated). 3. Think about why that''s ...”
September 5, 2018
GMATGuruNY posted a reply to If r is a positive integer, n=r^3 and 4,14, and 27 are facto in the Problem Solving forum
“Since 4, 14 and 27 are all factors of n, the prime-factorization of n must include 2*2, 2*7 and 3*3*3. n = r³ implies that n is a perfect cube. The prime-factorization of a perfect cube must include at least 3 of each prime factor. Thus, the prime-factorization of n must include at least three ...”
September 5, 2018
GMATGuruNY posted a reply to If x and y are integers, what is the least possible positive in the Problem Solving forum
“Make a list of integer options for |21x| and |35y|: |21x| = 0, 21, 42, 63, 84, 105... |35y| = 0, 35, 70, 105... The smallest positive sum is yielded in the following cases: 21x = 42 and 35y = -35, with the result that 21x + 35y = 42 - 35 = 7 21x = -63 and 35y = 70, with the result that 21x + ...”
September 4, 2018
GMATGuruNY posted a reply to absolute value in the Data Sufficiency forum
“if a < y < z < b , is |y-a| less than |y-b| ? 1) |z-a| < |z-b| 2) |y-a| < |z-b| |a-b| = the distance between a and b. Since a < y < z < b, we get the following number line: a..........y..........z..........b Statement 1: |z-a| < |z-b| Since the distance ...”
September 4, 2018
GMATGuruNY posted a reply to Triathlete Dan runs along a 2-mile stretch of river and then in the Problem Solving forum
“When the same distance is traveled at two different speeds, the average speed will be the same for ANY DISTANCE. Thus, we can solve the problem above using a distance that is divisible by the two speeds. Let the distance in each direction = 30 miles. Time to run 30 miles at a rate of 10 miles per ...”
September 4, 2018
GMATGuruNY posted a reply to permutation/combination in the Problem Solving forum
“Mr. Smith shook hands with 3 times as many men as women. The phrase in blue implies that the number of men who shook hands with Mr. Smith is a MULTIPLE OF 3. Thus, the total number of men = (multiple of 3) + (Mr. Smith). In math terms: Number of men = 3a + 1, where a is a positive integer. ...”
September 4, 2018
GMATGuruNY posted a reply to GMATPREP Question - what is the subject in the Sentence Correction forum
“A comparison is questionable if it allows for more than one logical interpretation. Case 2 is not a logical interpretation of your revision of E. No reader will construe that what MANAGERS find is being compared to what A GRASPING finds. Since only Case 1 constitutes a logical interpretation, the ...”
September 4, 2018
GMATGuruNY posted a reply to At a certain hospital, 75% of the interns receive fewer than in the Problem Solving forum
“We can use a double-matrix: https://preview.ibb.co/iUwRPe/matrix_interns.png In the resulting matrix, total not tired = 19/100 = 19%. The correct answer is C.”
September 4, 2018
GMATGuruNY posted a reply to Points (x,y) in the rectangular coordinate plane in the Problem Solving forum
“Since the graph intercepts the x-axis to the left of the y-axis and has only one solution, its graph is as follows: y = (x-k)², where k<0. The equation above has an x-intercept at (k, 0), as shown in the figure above. The answer choices represent the sum of k (the x-intercept) and p (the ...”
September 4, 2018
GMATGuruNY posted a reply to Six children — A, B, C, D, E, and F — are going to sit i in the Problem Solving forum
“Alternate approach: Number of options for A = 6. (Any of the 6 chairs.) Number of options for B = 5. (Any of the 5 remaining chairs.) Number of options for C = 4. (Any of the 4 remaining chairs.) Number of options for D = 3. (Any of the 3 remaining chairs.) Number of options for E and F = 1. ...”
September 3, 2018
GMATGuruNY posted a reply to Is |xy|>x^2y^2 in the Data Sufficiency forum
“Looks good!”
September 2, 2018
GMATGuruNY posted a reply to 3 machines have a productivity ratio of 1 to 2 to 5. All 3 in the Problem Solving forum
“Let the rate for the fastest machine = 5 units per hour and the rate for the slowest machine = 1 unit per hour. Since the fastest machine works at a rate of 5 units per hour for all 9 hours, the work produced by the fastest machine = rt = 5*9 = 45 units. Since the slowest machine works at a rate ...”
September 2, 2018
GMATGuruNY posted a reply to Is x an integer? in the Data Sufficiency forum
“Statement 1: x/2 = 1, 2, 3, 4, 5... Multiplying every value by 2, we get: x = 2, 4, 6, 8, 10... In every case, x is an integer. SUFFICIENT. Statement 2: 2x = 1, 2, 3, 4, 5... Dividing every value by 2, we get: x = 1/2, 1, 3/2, 2, 5/2... If x=1/2, then x is not an integer. If x=1, then x ...”
September 2, 2018
GMATGuruNY posted a reply to integers in the Problem Solving forum
“If we use 0 as a placeholder -- so that 007 represents 7, 072 represents 72, etc. -- then we need to count the number of times that 7 will appear among the 3-digit integers from 000 to 999, inclusive. Total number of 3-digit integers from 000 to 999, inclusive = biggest - smallest + 1 = ...”
September 1, 2018
GMATGuruNY posted a reply to If x^2/9 – 4/y^2 = 12, what is the value of x? in the Data Sufficiency forum
“x²/9 – 4/y² = 12 (x/3)² - (2/y)² = 12 The resulting equation is the DIFFERENCE OF TWO SQUARES: a² - b² = (a+b)(a-b). Thus, the equation can be rephrased as follows: (x/3 + 2/y)(x/3 - 2/y) = 12. Statement 1: Substituting x/3 + 2/y = 6 into (x/3 + 2/y)(x/3 - 2/y) = 12, we get: ...”
September 1, 2018
GMATGuruNY posted a reply to Agatha Christie´s Escalator in the Problem Solving forum
“Algebraic approach: Let P = Poirot''s rate, M = Marple''s rate, and E = the escalator''s rate. Since P travels 3 steps for every 2 steps that M travels: P/M = 3/2. Ratios can be MULTIPLIED: P/E * E/M = P/M . Since P/M = 3/2, we get: P/E * E/M = 3/2 Let x = the number of steps on ...”
August 30, 2018
GMATGuruNY posted a reply to Agatha Christie´s Escalator in the Problem Solving forum
“Let P = Poirot''s rate, M = Marple''s rate, and E = the escalator''s rate. Since P travels 3 steps for every 2 steps that M travels: P/M = 3/2. Ratios can be MULTIPLIED: P/E * E/M = P/M Since P/M = 3/2, we get: P/E * E/M = 3/2. We can PLUG IN THE ANSWERS, which represent the number of ...”
August 30, 2018
GMATGuruNY posted a reply to If 4 is one solution of the equation x^2 + 3x + k = 10, in the Problem Solving forum
“Alternate approach: x² + 3x = 10-k x² + 3x = constant. Since x=4 and the correct answer choice are both roots, they must yield the same result when plugged into x² + 3x. Plugging x=4 into x² + 3x, we get: 4² + 3*4 = 28. If we test the answer choices, only x=-7 yields the same result ...”
August 30, 2018
GMATGuruNY posted a reply to A jar contains 16 red balls and 8 white balls. If 3 balls ar in the Problem Solving forum
“P(1st marble is white) = 8/24. (Of the 24 marbles, 8 are white.) P(2nd marble is white) = 7/23. (Of the 23 remaining marbles, 7 are white.) P(3rd marble is white) = 6/22. (Of the 22 remaining marbles, 6 are white.) To combine these probabilities, we multiply: 8/24 * 7/23 * 6/22 = 1/3 * 7/23 * ...”
August 30, 2018
GMATGuruNY posted a reply to In a certain summer school program, there are five periods in the Problem Solving forum
“Alternate approach: Since Science class must be followed immediately by Science lab, Science class cannot be taken during the last period. Thus: Number of options for Science class = 4. (Any of the first 4 periods.) Number of options for Science lab = 1. (Must be the period immediately after ...”
August 30, 2018
GMATGuruNY posted a reply to What is the value of j + k? in the Data Sufficiency forum
“Statement 1: Case 1: m=0, j=0, k=0 In this case, j+k = 0+0 = 0 Case 2: m=0, j=0, k=1 In this case, j+k = 0+1 = 1 Since j+k can be different values, INSUFFICIENT. Statement 2: Dividing both sides of the equation by 5, we get: j+k = 2. SUFFICIENT. The correct answer is B.”
August 30, 2018
GMATGuruNY posted a reply to Angela has 15 pairs of matched socks. If she loses 7 in the Problem Solving forum
“15 matched pairs = 30 socks. E: 12 If Angela has 12 matched pairs left -- for a total of 24 socks -- then the number of socks lost = 30-24 = 6. Not viable, since Angela must lose 7 socks. The correct answer is E.”
August 30, 2018
GMATGuruNY posted a reply to To fill a number of vacancies, an employer must hire 3 in the Problem Solving forum
“Number of ways to choose 3 programmers from 6 applicants = 6C3 = (6*5*4)/(3*2*1) = 20. Number of ways to choose 2 managers from 4 applicants = 4C2 = (4*3)/(2*1) = 6. To combine the options above, we multiply: 20*6 = 120. The correct answer is C.”
August 29, 2018
GMATGuruNY posted a reply to What is the units digit of (3^{101})(7^{103})? in the Problem Solving forum
“When an integer is raised to consecutive powers, the resulting units digits repeat in a CYCLE. 3¹⁰¹: 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 ...”
August 29, 2018
GMATGuruNY posted a reply to It takes the high-speed train x hours to travel the z miles in the Problem Solving forum
“Plug in easy numbers for the two rates. Then plug in a distance that is a multiple of both the two individual rates and the COMBINED rate. Let the high speed rate = 3 miles per hour. Let the regular rate = 2 miles per hour. Combined rate for the trains = 2+3 = 5 miles per hour. Let z = ...”
August 28, 2018
GMATGuruNY posted a reply to The world wildlife fund has declared that global warming in the Sentence Correction forum
“a phenomenon that is caused by human beings. Here, the that-clause in green serves to modify a phenomenon. Question: What KIND of phenomenon? Answer: A phenomenon THAT IS CAUSED BY HUMAN BEINGS. Most scientists agree that the statement above is true. To convey this meaning, we insert most ...”
August 28, 2018
GMATGuruNY posted a reply to November is traditionally the strongest - OG 2018 in the Sentence Correction forum
“Incorrect: When compared with most sport utility vehicles, minivans get better gas mileage. Here, the usage of when compared is unwarranted and conveys a nonsensical meaning, implying that minivans GET better mileage at the same time as they are COMPARED. The following is sufficient to convey the ...”
August 28, 2018
GMATGuruNY posted a reply to How many different positive integers having six digits are in the Problem Solving forum
“How many ways can the letters BBBGG be arranged? Number of ways to arrange 5 elements = 5!. But when an arrangement includes IDENTICAL elements, we must divide by the number of ways each set of identical elements can be ARRANGED. The reason: When the identical elements swap positions, the ...”
August 28, 2018
GMATGuruNY posted a reply to A certain IT department of fewer than 15 people hires coders in the Data Sufficiency forum
“Let c = coders and s = system administrators. Statement 1: 55,000(c-2) + 45,000(s+2) = 535,000 55(c-2) + 45(s+2) = 535 11(c-2) + 9(s+2) = 107. Implication of the resulting equation: (multiple of 11) + (multiple of 9) = 107. (multiple of 9) = 107 - (multiple of 11). Subtract ...”
August 28, 2018
GMATGuruNY posted a reply to Justin, Max, and Paul each have a collection of marbles. in the Problem Solving forum
“Since Max has 30% more than Paul''s 80 marbles, Max = 80 + (3/10)(80) = 104. Since Justin has 50% fewer than Max''s 104 marbles, Justin = (1/2)(104) = 52. The correct answer is C.”
August 28, 2018
GMATGuruNY posted a reply to How many different positive integers having six digits are in the Problem Solving forum
“There are 6 positions in the integer. The two 4''s must occupy a pair of positions. From the 6 positions, the number of ways to choose a pair for the two 4''s = 6C2 = (6*5)/(2*1) = 15. The remaining 4 positions must be occupied by 3, 5, 7 or 8, 7 or 8. Number of options for the 3 = 4. (Any ...”
August 28, 2018
GMATGuruNY posted a reply to George bought a large electronic item with a 15% off coupon, in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the original price of the item. When the correct answer is plugged in, George reimburses the store $40.50. Since the coupon discount = 15% = 15/100 = 3/20, the original price of the item is almost certainly a multiple of 20. Of the 5 answer choices, ...”
August 27, 2018
GMATGuruNY posted a reply to Exactly 8 years ago, Jim's son was twice as old as Jim's in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the daughter''s current age. When the correct answer is plugged in, the nd the dau B: 10, implying that the daughter''s age 8 years ago = 10-8 = 2 Since the son 8 years ago was twice as old as the daughter, the son''s age 8 years ago = 2*2 = 4, ...”
August 27, 2018
GMATGuruNY posted a reply to If m and r are two numbers on a number line, what is the in the Data Sufficiency forum
“Translate the words into math. The DISTANCE between x and 0 is |x|. HALFWAY between two numbers is the AVERAGE of the two numbers. Statement 1: The distance between r and 0 is 3 times the distance between m and 0. |r| = 3|m| r = 3m or r=-3m. No way to solve for r. INSUFFICIENT. ...”
August 27, 2018
GMATGuruNY posted a reply to If a, b, and c are positive integers, what is the remainder in the Data Sufficiency forum
“Clearly, neither statement is sufficient on its own. Statements combined: The statements indicate that a and b are CONSECUTIVE PERFECT CUBES. Make a list of perfect cubes: 1, 8, 27, 64, 125... Calculating the difference between one perfect cube and the next, we get: 8-1 = 7 27-8 = 19 ...”
August 27, 2018
GMATGuruNY posted a reply to GMAT Prep Problem 1 in the Problem Solving forum
“Let the amount saved each month = $1. Total saved for the entire year = 12*1 = $12. Since the total saved for the entire year -- $12 -- is 3 times the total not saved each month, the total not saved each month = 12/3 = $4. Thus, the total monthly pay = (total saved each month) + (total not saved ...”
August 27, 2018
GMATGuruNY posted a reply to GMAT Prep Problem 3 in the Problem Solving forum
“The prompt requires the following: (greatest integer)(next largest integer) < 200. The answer choices imply that the greatest integer must be 13, 14, 15, or 20 15² = 225 and 20² = 400. Implication: (15)(next largest integer) and (20)(next largest integer) will each yield a product greater ...”
August 27, 2018
GMATGuruNY posted a reply to Solution X, which is 50% alcohol, is combined with solution in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the amount of Y. Since the percentage for the mixture (35%) is closer to Y''s percentage (30%) than to X''s percentage (50%), Y must constitute MORE THAN 1/2 of the 16-liter mixture. Thus, the amount of Y must be equal to more than 8 liters. Eliminate ...”
August 27, 2018
ceilidh.erickson posted a reply to Confusing parallelism (never seen before) in the Sentence Correction forum
“I agree that this is unusual. "Flash" and "cover" here are not declarative verbs; they are imperatives (commands), and thus do not need a subject. Normally, we wouldn''t see imperatives on the GMAT, as they imply that one person is speaking to another: "Go to bed! Brush ...”
August 27, 2018
ceilidh.erickson posted a reply to If a, b, and c are positive integers, what is the remainder in the Data Sufficiency forum
“Another option is to test values. As Jay said, we need information about both b and a, so neither statement will be sufficient on its own. When we combine the statements, we can test values: Case 1: c = 1 a = 1^3 = 1 b = 2^3 = 8 b - a = 8 - 1 = 7 the remainder when 7 is divided by 3 is 1. ...”
August 27, 2018
ceilidh.erickson posted a reply to If Mary always takes the same route to work, how long did it in the Data Sufficiency forum
“Given that the distance to work is always the same, we want to know the TIME that it took to get to work on Friday. (1) It took Mary 20 minutes to get to work on Thursday. We are given no relationship between Thursday and Friday - this might be faster, slower, or the same. Insufficient. (2) ...”
August 27, 2018
ceilidh.erickson posted a reply to ABCD is a square picture frame (see figure). EFGH is a in the Problem Solving forum
“If the length AB = 6, then the area of the entire figure (frame + picture) = 36. Since the frame and picture both have an equal area, the area of each must be 18. If square EFGH has an area of 18, then each side length must be: $$\sqrt{18}$$ $$=3\sqrt{2}$$ The answer is D.”
August 27, 2018
ceilidh.erickson posted a reply to Male bowerbirds construct elaborately decorated nests, or in the Critical Reasoning forum
“This question is testing CORRELATION v. CAUSATION logic. Given: The building styles of bowerbirds of the same species are different in different locations. Conclusion: Building styles are culturally acquired, not genetic. Logical Gap: - are these birds in different locations genetically ...”
August 27, 2018
ceilidh.erickson posted a reply to A car dealership has 40 cars on the lot, 30% of which are in the Problem Solving forum
“Original: 30% of 40 cars are silver --> 12 cars are silver. New shipment: 40% are NOT silver --> 60% are silver 60% of 80 cars --> 48 silver cars Total: silver: 12 + 48 = 60 all: 40 + 80 = 120 60/120 = 50% of all cars are silver The answer is E.”
August 27, 2018
ceilidh.erickson posted a reply to Solution X, which is 50% alcohol, is combined with solution in the Problem Solving forum
“This is a WEIGHTED AVERAGE question. With any mixture, the resulting solution will be closer in composition to whichever component we added more of. In other words, if we add more of a 50% solution, the resulting mixture will be closer to 50%, and if we add more of the 30% solution, the ...”
August 27, 2018
ceilidh.erickson posted a reply to Shawana made a schedule for reading books during 4 weeks in the Problem Solving forum
“The easiest (though perhaps not the most elegant) way to approach this problem is to chart it out. For each book, divide the number of pages by 50, then round up if there is a remainder. For example, 253/50 = 5 remainder 3 --> round up to 6 days total. Book #:----Days to read:---Total ...”
August 27, 2018
GMATGuruNY posted a reply to Each of the cucumbers in 100 pounds is composed of 99% water in the Problem Solving forum
“Since the cucumbers are 99% water, the 100 pounds of cucumbers are composed of 99 pounds of water and 1 POUND OF OTHER STUFF. After evaporation makes the cucumbers 98% water, the 1 POUND OF OTHER STUFF must constitute 2% of the new total: 1 = (2/100)x x = 100/2 = 50. The correct answer ...”
August 26, 2018
GMATGuruNY posted a reply to Of the 9,000 people who voted in a recent election, how many in the Data Sufficiency forum
“Statement 1: (women for X) : (women against X) = 2:1. Of every 3 women voters, 2 voted for X, while 1 voted against X. In other words, 2/3 of women voters voted for X. No way to determine the NUMBER of women who voted for X. INSUFFICIENT. Statement 2: No info about women voters. ...”
August 26, 2018
GMATGuruNY posted a reply to The sum of positive integers x and y is 77, what is the in the Data Sufficiency forum
“Statement 1: Substituting x=y+1 into x+y = 77, we get: (y+1) + y = 77 2y = 76 y = 38, implying that x = 38+1 = 39. Thus, xy = 39*38. SUFFICIENT. Statement 2: For x and y to have the same tens digit and a sum of 77, they must be equal to the pair of values yielded by Statement 1: 38 and ...”
August 26, 2018
GMATGuruNY posted a reply to If n = 10^10 and n^n = 10^d, what is the value of d? A. 10^ in the Problem Solving forum
“Substituting n= 10¹⁰ into n^n = 10^d, we get: (10¹⁰ )^(10¹⁰)= 10^d When an exponent is raised to a power, we MULTIPLY the exponents. Multiplying the exponents in blue, we get: 10^(10*10¹⁰) = 10^d 10^(10¹¹) = 10^d Since each side has the same base, the exponent in blue must be ...”
August 26, 2018
GMATGuruNY posted a reply to How many five-digit numbers can be formed from the digits in the Problem Solving forum
“For the 5-digit integer to be a multiple of 4, the last two digits must form a multiple of 4. Options: 04, 12, 20, 24, 32, 40, 52. Case 1: Last 2 digits include 0 Number options for the last 2 digits = 3. (04, 20 or 40.) Number of options for the ten-thousands place = 4. (Any of the 4 ...”
August 25, 2018
GMATGuruNY posted a reply to Michael drives x miles due north at arrives at Point A. He in the Problem Solving forum
“In deference to Brent''s concerns, the problem should read as follows: x miles north, y miles east, and z miles in a straight line back to x constitute a right triangle with legs x and y and hypotenuse z. The only right triangle in which all 3 sides are integers and the shortest leg is 5 is ...”
August 24, 2018
GMATGuruNY posted a reply to The average (arithmetic mean) of the five numbers in a data in the Problem Solving forum
“Sum = (quantity)(average). The average (arithmetic mean) of the five numbers in a data set is 72. Sum = 5*72 = integer with a UNITS DIGIT OF 0. The average (arithmetic mean) of the first three numbers is 98. Sum = 3*98 = integer with a UNITS DIGIT OF 4. For the sum of all 5 numbers to ...”
August 24, 2018
GMATGuruNY posted a reply to Linda and Angela contract to paint a neighbor's house. Even in the Problem Solving forum
“Let the pay rate = $1 per hour. Let Angela''s time = 4 hours. Since Linda works 50% longer, Linda''s time = 4 + (1/2)4 = 6 hours. Since a total of 10 hours are worked at a rate of $1 per hour, the total pay = 10*1 = $10. Since each worker receives m dollars of the total pay, m=$5. Since ...”
August 23, 2018
GMATGuruNY posted a reply to United Telephone charges a base rate of $10.00 for service, in the Problem Solving forum
“An alternate approach is to PLUG IN THE ANSWERS. When the correct answer is plugged in, the two companies will charge the same amount. B: 10 minutes Since United charges $10 plus $0.25 per minute, the charge from United = 10 + 10(0.25) = $12.50. Since Atlantic charges $12 plus $0.20 per ...”
August 23, 2018
GMATGuruNY posted a reply to A whole number greater than 1 has remainders of 1 when it is in the Problem Solving forum
“We can PLUG IN THE ANSWERS. To yield a remainder of 1 when divided by 4, the correct answer must be 1 more than a multiple of 4. The smallest answer choice that is 1 more than a multiple of 4 is 61. When 61 is divided by 2, 3 or 5, the remainder is 1 in each case. The correct answer is C.”
August 23, 2018
GMATGuruNY posted a reply to One woman and one man can build a wall together in two hours in the Problem Solving forum
“One woman and one man can build a wall together in two hours, but the woman would need the help of two girls in order to complete the same job in the same amount of time. Since replacing 1 man with 2 girls does not change the amount of time required to complete the job, 1 man is the equivalent of 2 ...”
August 23, 2018
GMATGuruNY posted a reply to What is the decimal equivalent of (1/5)^5? in the Problem Solving forum
“1/5⁵ = = (1/25)(1/25)(1/5) = (4/4 * 1/25)(4/4 * 1/25)(2/2 * 1/5) = (4/100)(4/100)(2/10) = 32/100000 = 32 * 10ˉ⁵ = 0.00032 The correct answer is A.”
August 22, 2018
GMATGuruNY posted a reply to While it costs about the same in the Sentence Correction forum
“Correct! OA: The cost of running nuclear power plants is about the same as is the cost] for other types of power plants. The blue verb in brackets is omitted but implied.”
August 22, 2018
GMATGuruNY posted a reply to Five friends Alastair, Bell, Cook, Darren and Eoin appeared in the Problem Solving forum
“To determine the ratio of the scores, plug in numbers and reduce the resulting ratio as much as possible. Let A = Alastair, B = Bell, C = Cook, D = Darren, and E = Eoin. Let B = the product of the denominators = 2*5*5*2 = 100. Darren’s score was 3/2 times that of Bell’s score. D = 3/2(B) = ...”
August 22, 2018
GMATGuruNY posted a reply to While it costs about the same in the Sentence Correction forum
“The OA implies the following: The cost of running nuclear power plants is about the same as for other types of power plants. The prepositions phrase in blue serves the same function as the prepositional phrase in red: both serve to modify the cost.”
August 21, 2018
GMATGuruNY posted a reply to While it costs about the same in the Sentence Correction forum
“to run for X implies that X is a GOAL. Mary plans to run for president. Conveyed meaning: The office of president = Mary''s goal. Thus, to run for other types of power plants implies that OTHER TYPES OF POWER PLANTS constitute a goal. Not the intended meaning. No one is attempting to reach ...”
August 21, 2018
GMATGuruNY posted a reply to While it costs about the same in the Sentence Correction forum
“OA: The cost of running nuclear power plants is about the same as for other types of power plants. Since the blue portion provides its own referent (other types of power plants), the referent in the red portion (nuclear power plants) is not implied in the blue portion. C: It costs about the ...”
August 21, 2018
ceilidh.erickson posted a reply to GMAT Official Guide 2019 A prominent investor who holds in the Critical Reasoning forum
“I''d like to add a bit of advice to Brent''s for boldface questions: Once you''ve determined the role of each statement in generic terms, don''t read through each entire answer choice. Instead, read just the 1st part first and eliminate. Then look at the 2nd part only for the answer choices that ...”
August 21, 2018
ceilidh.erickson posted a reply to For what percent of those tested for a certain infection was in the Data Sufficiency forum
“For more on how to use Double Set Matrices for similar problems, see: https://www.beatthegmat.com/in-a-product-test-of-a-common-cold-remedy-x-percent-of-the-t303696.html#818274 https://www.beatthegmat.com/retailers-question-t42509.html#809549 ...”
August 21, 2018
ceilidh.erickson posted a reply to For what percent of those tested for a certain infection was in the Data Sufficiency forum
“The best way to approach this question is with a DOUBLE SET MATRIX. There are 2 relevant questions here: 1. Does a person have the infection or not? 2. Have they tested positive or not? https://s22.postimg.cc/rx9c6dqj1/Screenshot_2018-08-21_15.12.10.png Accurate results will be those who ...”
August 21, 2018
GMATGuruNY posted a reply to If x and y are prime numbers, how many factors has x^2y^2? in the Data Sufficiency forum
“To count the positive factors of a positive integer: 1. Prime-factorize the integer 2. Write the prime-factorization in the form (a^p)(b^q)(c^r)... 3. The number of factors = (p+1)(q+1)(r+1)... Generally, GMAT problems about factors are constrained to POSITIVE factors. On the GMAT, the posted ...”
August 21, 2018
GMATGuruNY posted a reply to One machine, working at a constant rate, can fill a certain in the Problem Solving forum
“Time and rate have a RECIPROCAL RELATIONSHIP. If Mary works TWICE as fast as John, Mary''s time will be 1/2 John''s time. If Mary works THREE TIMES as fast as John, Mary''s time will be 1/3 John''s time Since 4 machines will work 4 times as fast as 1 machine, the time for 4 machines will ...”
August 21, 2018
ceilidh.erickson posted a reply to By applying optimization techniques commonly used to plan in the Sentence Correction forum
“This question is primarily testing OPENING MODIFIERS. The sentence begins with the opening modifier By applying optimization techniques commonly used to plan operations,... This must be followed by the SUBJECT being modified, i.e. the person(s) or thing(s) applying these techniques. (A) it is ...”
August 21, 2018
ceilidh.erickson posted a reply to When working with overseas clients, an understanding of cult in the Sentence Correction forum
“This question is testing MODIFIERS and PARALLELISM/COMPARISONS. (A) When working with overseas clients, an understanding of cultural norms is at least as important as grasping the pivotal business issues for the global manager. - "when working..." is an opening modifier. It must ...”
August 21, 2018
ceilidh.erickson posted a reply to Over the past few years, retailers in the town of in the Critical Reasoning forum
“When you''re looking to WEAKEN (cast doubt) on an argument, you must first find where the chain of logic is broken. Look for an unstated assumption that would be needed to connect the premises to the conclusion. Premises: - retailers in the town of Statesville have suffered from decreasing ...”
August 21, 2018
GMATGuruNY posted a reply to Which of the following is the best approximation for 11^11-9 in the Problem Solving forum
“Another approach: 10¹¹ (100,000,000,000) is 100 TIMES the value of 10⁹ (1,000,000,000). Implication: 11¹¹ must be MORE THAN 100 TIMES the value of 9⁹. Since 9⁹ is so small when compared to 11¹¹, we can ignore the value of 9⁹ when we approximate: 11¹¹ - 9⁹ ≈ 11¹¹ The ...”
August 21, 2018
GMATGuruNY posted a reply to Which of the following is the best approximation for 11^11-9 in the Problem Solving forum
“Since the answer choices are very spread out, our approximation does not have to very exact. 11¹¹−9⁹ = 11¹¹− (11−2)⁹ ≈ 11¹¹ − 11⁹ = 11⁹(11²−1) ≈ (11⁹)(11²) = 11¹¹ The correct answer is D.”
August 21, 2018
GMATGuruNY posted a reply to Of 30 applicants for a job, 14 had at least 4 years' in the Problem Solving forum
“One approach is to use the following equation: Total = Group 1 + Group 2 - Both + Neither The big idea is to SUBTRACT THE OVERLAP. In the problem above, there is an overlap between the applicants with at least 4 years'' experience and the applicants with degrees. Some applicants belong to BOTH ...”
August 21, 2018
GMATGuruNY posted a reply to Which of the following points could lie in the same quadrant in the Problem Solving forum
“Every answer choice includes at least one negative sign. Test coordinate pairs that include at least one negative value. Case 1: a=1 and b=-1, so that (a, b) = (1, -1) Plug a=1 and b=-1 into the answer choices to see whether one of the answer choices yields a point in the same quadrant as ...”
August 21, 2018
GMATGuruNY posted a reply to If a and b are positive integers and x = 4^a and y = 9^b, in the Problem Solving forum
“x is equal to a POWER OF 4: 4, 16, 64... y is equal to a POWER OF 9: 9, 81... If x=4 and y=81, then xy = 324, which has a units digit of 4. The correct answer is B.”
August 21, 2018
GMATGuruNY posted a reply to Is z an even integer? in the Data Sufficiency forum
“Statement 1: Make a list of options for z/2: z/2 = 0, 2, 4, 6, 8... To get a list of options for z, multiply every value by 2: z = 0, 4, 8, 12, 16... In every case, z is an even integer, so the answer to the question stem is YES. SUFFICIENT. Statement 2: Make a list of options for 3z: 3z ...”
August 21, 2018
ceilidh.erickson posted a reply to A recent United States Census Bureau report shows that there in the Sentence Correction forum
“This question is testing COMPARISONS and IDIOMS. The correct idiom is AS MANY ____ AS ____. We can eliminate any answers that use "than": D and E. We can also eliminate the incorrect "as compared to" in A. The larger comparison structure is "there are 3x as many ...”
August 20, 2018
ceilidh.erickson posted a reply to If n is an integer between 10 and 100, is the tens digit of in the Data Sufficiency forum
“For digit questions in DS, the best strategy is often to test values. (1) The remainder when n is divided by 4 is equal to the remainder when n is divided by 5. This tells us that either n must be a multiple of 20 (multiple of both 4 and 5), or some multiple of 20 + 1, +2, or +3 (if we add 4 ...”
August 20, 2018
ceilidh.erickson posted a reply to If a is an integer, what is the units digit of a^18? (1) a^ in the Data Sufficiency forum
“For more on patterns in units digits, see: https://www.beatthegmat.com/what-is-the-units-digit-of-a-36-a-a-2-has-9-as-the-u-t151317.html#544267 https://www.beatthegmat.com/if-r-s-and-t-are-all-positive-integers-t17201.html#548713 ...”
August 20, 2018
ceilidh.erickson posted a reply to If a is an integer, what is the units digit of a^18? (1) a^ in the Data Sufficiency forum
“If we want to know the units digit of a^18, we must know something about the units digit of a. (1) a^2 has a units digit of 9 Test digits to see if there is more than one units digit that will yield a 9 when squared: a = 1 --> a² = 1 --> no. a = 2 --> a² = 4 --> no. a = ...”
August 20, 2018
ceilidh.erickson posted a reply to For the list of numbers above there is exactly one mode. Is in the Data Sufficiency forum
“You neglected to list / screenshot the "numbers above."”
August 20, 2018
GMATGuruNY posted a reply to Set S consists of all prime integers less than 10 in the Problem Solving forum
“It is not possible for the two products -- that of the two chosen numbers and that of the two unchosen numbers -- to be equal. Each of the two products has the same probability of being greater. Thus, the probability that the product of the two chosen numbers is greater = 1/2. The correct ...”
August 20, 2018
GMATGuruNY posted a reply to How many days after the purchase of product X does its in the Data Sufficiency forum
“Statement 1: Minimum number of days: purchase date = January 31, expiration date = March 1 Here, the expiration date = (28 days of February) + (first day of March) = 29 days after purchase. Maximum number of days: purchase date = January 1, expiration date = March 31 Here, the expiration date ...”
August 19, 2018
GMATGuruNY posted a reply to Collectively, the five children in the Kramer family have 30 in the Problem Solving forum
“In ascending order, let the 5 trophy values be a, b, c, d and e. To maximize the value of d -- the second highest value -- we must MINIMIZE the values of a, b and c. Since every child must have a different number of trophies, the least possible values for a, b and c are a=1, b=2, and c=3. Since ...”
August 18, 2018
GMATGuruNY posted a reply to Mona and Donald fly to Rome for the weekend. They take cash in the Problem Solving forum
“We can PLUG IN THE ANSWERS, which represent the total number of notes. The number of €10 notes they take is double the number of $10 notes they take. Thus, the ratio of €10 notes to $10 notes = 2:1. Since the sum of the parts of this ratio = 2+1 = 3, the total number of notes must be a ...”
August 18, 2018
GMATGuruNY posted a reply to A certain junior class has 1,000 students and a certain in the Problem Solving forum
“P(sibling pair) = (total number of sibling pairs)/(total number of possible pairs). Total number of possible pairs: There are 1000 juniors and 800 seniors. Total number of ways to combine 1 junior with 1 senior = 1000*800 = 800,000. Total number of sibling pairs = 60. Thus: ...”
August 17, 2018
GMATGuruNY posted a reply to Jason can stack two shelves in 3 hours and Maria can stack in the Problem Solving forum
“Let each shelf = 6 pounds. Since Jason takes 3 hours to stack 2 6-pound shelves -- for a total of 12 pounds -- Jason''s rate = 12/3 = 4 pounds per hour. Since Maria takes 2 hours to stack 3 6-pound shelves -- for a total of 18 pounds -- Maria''s rate = 18/2 = 9 pounds per hour. Total weight of 13 ...”
August 16, 2018
GMATGuruNY posted a reply to GPREP 3 SC-9 in the Sentence Correction forum
“Fixed! Thanks for catching the typo.”
August 16, 2018
GMATGuruNY posted a reply to Is n an integer less than 5? in the Data Sufficiency forum
“Statement 1: Make a list of options for 5n: 5n = 1, 2, 3, 4, 5... To get a list options for n, divide every value above by 5: n = 1/5, 2/5, 3/5, 4/5, 1... If n = 1/5, the answer to the question stem is NO. If n = 1, the answer to the question stem is YES. INSUFFICIENT. Statement 2: Make a ...”
August 16, 2018
GMATGuruNY posted a reply to A company hired a printer to produce a total of x + 1 in the Problem Solving forum
“The company requested 3 more 2¢ envelopes than 5¢ envelopes. Let the number of 5¢ envelopes = 2, and the number of number of 2¢ envelopes = 2+3 = 5, with the result that the cost of the envelopes = (5*2) + .(2*5) = 20 cents. A company hired a printer to produce a total of x + 1 envelopes. ...”
August 16, 2018
GMATGuruNY posted a reply to A librarian has a set of ten books, including four different in the Problem Solving forum
“Since the 4 Lincoln books must be side-by-side, place them in a BLOCK: C.”
August 16, 2018
GMATGuruNY posted a reply to A vending machine randomly dispenses four different types in the Problem Solving forum
“There are twice as many strawberry candies as grape candies. If G=1, then S=2. There are twice as many apple candies as strawberry candies. If S=2, then A=4. There are twice as many apple candies as orange candies. If A=4, then O=2. Resulting ratio: G:S:A:O = 1:2:4:2. Since the sum of the ...”
August 16, 2018
GMATGuruNY posted a reply to Three copying machines A, B, and C, working together at in the Problem Solving forum
“Let the job = 8 pages. Since A+B+C take 2 hours to copy the 8-page job, the combined rate for A+B+C = 8/2 = 4 pages per hour. Since B+C take 4 hours to copy the 8-page job, the combined rate for B+C = 8/4 = 2 pages per hour. A''s rate = (rate for A+B+C) - (rate for B+C) = 4-2 = 2 pages per ...”
August 15, 2018
GMATGuruNY posted a reply to (x – 1)(y – 1) = 1? in the Data Sufficiency forum
“Alternate approach: Statement 1: Case 1: x=2 Substituting x=2 into x+y = xy, we get: 2 + y = 2y 2 = y. In this case, (x-1)(y-1) = (2-1)(2-1) = 1, so the answer to the question stem is YES. Case 2: x=3 Substituting x=3 into x+y = xy, we get: 3+ y = 3y 3 = 2y 3/2 = y. In this case, ...”
August 15, 2018
GMATGuruNY posted a reply to Students are in clubs as follows: Science-20, Drama-30, and in the Problem Solving forum
“When we count the total in Science, the total in Drama, and the total in Band, any students in exactly two of the clubs are counted TWICE. Thus, we must SUBTRACT these students so that they are not double counted: Total = Science + Drama + Band - (exactly 2 clubs) = 20 + 30 + 12 - (8+6+4) = 44. ...”
August 15, 2018
GMATGuruNY posted a reply to Uncle Bruce is baking chocolate chip cookies. He has 36 in the Problem Solving forum
“= Since chocolate must constitute 20% of the cookies, the 36 ounces of dough must constitute the remaining 80%: 36 = 0.8x x = 36/0.8 = 360/8 = 45 ounces. Since the cookies = 45 ounces, and the dough = 36 ounces, the amount of chocolate used = 45-36 = 9 ounces. Thus -- of the 15 ounces of ...”
August 15, 2018
GMATGuruNY posted a reply to Three printing presses, R, S, and T, working together at the in the Problem Solving forum
“Let the job = 20 pages. Since R+S+T take 4 hours to print the 20-page job, the combined rate for R+S+T = 20/4 = 5 pages per hour. Since S+T take 5 hours to print the 20-page job, the combined rate for S+T = 20/5 = 4 pages per hour. R''s rate = (rate for R+S+T) - (rate for S+T) = 5-4 = 1 page per ...”
August 14, 2018
GMATGuruNY posted a reply to If a number between 0 and 1 is selected at random, which of in the Problem Solving forum
“Put the ranges over the same DENOMINATOR: A: 0 and 3/20 B. 30/20 and 1/5 -- 3/20 and 4/20 C. 1/5 and 1/4 --> 4/20 and 5/20 D. 1/4 and 3/10 --> 5/20 and 6/20 E. 3/10 and 1/2 --> 6/20 and 10/20 Since the greatest range is offered by E (10/20 - 6/20 = 4/20), the number is most likely ...”
August 14, 2018
GMATGuruNY posted a reply to Lyme disease is caused by a bacterium transmitted to humans in the Critical Reasoning forum
“E, rephrased as a basic statement: The other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans. The conclusion is constrained to the number of ticks infected with the bacterium that causes LYME DISEASE. Information about other bacteria is irrelevant ...”
August 14, 2018
GMATGuruNY posted a reply to Ben is driving on the highway at x miles per hour. (One mile in the Problem Solving forum
“Note: One revolution = one CIRCUMFERENCE. Let x = 2 miles per hour, implying that the distance traveled in 1 hour = 2*5280 = 10560 feet. Let y = 10 feet. Since the total distance traveled in 1 hour = 10560 feet, and each circumference = 10 feet, the number of revolutions in 1 hour = 10560/10 = ...”
August 14, 2018
GMATGuruNY posted a reply to Bob invests 100 dollars in a fund that yileds 15% simple in the Problem Solving forum
“Alternate approach: To earn exactly $100 in interest at rate of $15 earned each month, the number of months required = 100/15 = 20/3 = 6.66 months. The smallest integer greater than 6.66 is 7. Implication: After 7 months, the total amount of interest will for the first time EXCEED $100, with ...”
August 14, 2018
GMATGuruNY posted a reply to When x is divided by 2, the remainder is 1 and y is divided in the Problem Solving forum
“Algebraic approach: When x is divided by 2, the remainder is 1. In other words, x is a multiple of 2 plus 1: x = 2a + 1. When y is divided by 8, the remainder is 2. In other words, y is a multiple of 8 plus 2: y = 8b + 2. Thus: 2x + y = 2(2a+1) + (8b + 2) = 4a + 2 + 8b + 2 = 4a + 8b + ...”
August 14, 2018
GMATGuruNY posted a reply to Stacy and Katie plan to walk the 27-mile scenic route across in the Problem Solving forum
“Since Stacy and Katie travel toward each other, they WORK TOGETHER to cover the 27 miles between them. Since Stacy is 1/4 faster than Katie, for every 4 miles that Katie travels, the distance traveled by Stacy = 4 + (1/4)(4) = 5 miles. Thus, of every 9 miles traveled when Stacy and Katie work ...”
August 14, 2018
ceilidh.erickson posted a reply to If the vertices of a triangle have coordinates (x, 1), in the Data Sufficiency forum
“This seems to be a different question than the one Jay has quoted. Did you accidentally change it when editing?”
August 13, 2018
ceilidh.erickson posted a reply to In a product test of a common cold remedy, x percent of the in the Data Sufficiency forum
“One easy way to organize overlapping sets questions is with a Double Set Matrix: https://s22.postimg.cc/wf2tf7c0t/Screenshot_2018-08-13_16.11.03.png We''re looking for those who experienced both as a percent of the total: https://s22.postimg.cc/tkzo227d9/Screenshot_2018-08-13_16.12.45.png ...”
August 13, 2018
ceilidh.erickson posted a reply to Political Candidate: Government subsidized prescription drug in the Critical Reasoning forum
“Please edit your post - no bold text appears here.”
August 13, 2018
ceilidh.erickson posted a reply to If the average of 993, 994, 996, 997, 998, 1001, 1001, 1002, in the Problem Solving forum
“We can also treat this as a weighted average. Find how much each term differs from the average of 999: 993 --> -6 994 --> -5 996 --> -3 997 --> -2 998 --> -1 1001 --> +2 1001 --> +2 1002 --> +3 1004 --> +5 Quickly eliminate the ones that cancel each ...”
August 13, 2018
ceilidh.erickson posted a reply to CEO: Over the past several years, we have more than doubled in the Critical Reasoning forum
“Deloitte, I think you have a typo. You marked the correct answer "incorrect."”
August 13, 2018
ceilidh.erickson posted a reply to The airline company, following through on recent warnings in the Sentence Correction forum
“This question is testing PARALLELISM in a list. If we simplify the sentence, it would read: The airline company... announced that it was 1. eliminating jet service to nine cities 2. closing some unneeded operations, and 3. it grounded twenty-two planes. This is clearly not a parallel ...”
August 13, 2018
ceilidh.erickson posted a reply to The work of Byron and Shelley, like other poets of their era in the Sentence Correction forum
“This question is testing COMPARISONS and MODIFIERS. A. The work of Byron and Shelley, like other poets of their era, explored themes of love and beauty, which gave rise to the school of poetry known as Romanticism. - "work" can''t be like "other poets." We''d have to say ...”
August 13, 2018
ceilidh.erickson posted a reply to GMAT Official Guide 2019 In countries where automobile in the Critical Reasoning forum
“The goal in any BOLDFACE question is to deconstruct the argument, and determine the role of each statement: - author''s conclusion / position - support for the author - the counterpoint / what others believe - support for the counterpoint - neutral / background information This whiplash ...”
August 13, 2018
GMATGuruNY posted a reply to If the average of 993, 994, 996, 997, 998, 1001, 1001, 1002, in the Problem Solving forum
“Sum of the 10 terms = (quantity)(average) = 10*999 = 9990. If we add the units digits of the nine given terms, we get: 3+4+6+7+8+1+1+2+4 = 36. The sum of the nine given terms has a units digit of 6. The sum of all ten terms has a units digit of 0. Since (units digit of 6) + (units digit of 4) = ...”
August 12, 2018
GMATGuruNY posted a reply to Are all of the terms in Set A equal? in the Data Sufficiency forum
“I posted a solution to a very similar problem here: https://www.beatthegmat.com/from-og-12-t73239.html”
August 12, 2018
GMATGuruNY posted a reply to profit and loss in the Problem Solving forum
“Let r=0, implying that no profit is made and that the oranges are sold at cost. Let q=12, implying that the cost for 12 oranges is $12, with the result that the cost per orange = $1. 1.66 dozen = (5/3)(12) = 20 oranges. Since the cost for 20 oranges = $20, p=20. Thus: 5pq - 12r = (5*20*12) - ...”
August 11, 2018
GMATGuruNY posted a reply to In each game of a certain tournament, a contestant either in the Data Sufficiency forum
“Here is an algebraic way to combine the two statements: Let G = a game that results in a 2-point gain and L = a game that results in a 3-point loss. Statement 1: Since the played games yield a total of 4 points beyond the intital 100 points, we get: 2G - 3L = 4 2G = 4 + 3L Note: Since the ...”
August 10, 2018
GMATGuruNY posted a reply to In a home library consisting of 108 books, some hardcover in the Problem Solving forum
“Goal: To MAXIMIZE the number of nonfiction books. Since the fraction of hardcover books that are nonfiction (2/3) is greater than the fraction of softcover books that are nonfiction (1/4), the number of nonfiction books will be maximized if we must MAXIMIZE THE NUMBER OF HARDCOVER BOOKS. ...”
August 10, 2018
GMATGuruNY posted a reply to A family consisting of one mother, one father, two daughters in the Problem Solving forum
“Case 1: One daughter in the front passenger seat: Since one of the 2 parents must drive, number of choices for the driver''s seat = 2. Since either of the 2 daughters can be in the front passenger seat, number of choices = 2. Number of ways to arrange the 3 remaining people = 3! = 6. To combine ...”
August 10, 2018
GMATGuruNY posted a reply to mgmat 4 in the Data Sufficiency forum
“Fixed! Thanks for pointing out the typo.”
August 10, 2018
ceilidh.erickson posted a reply to In the circle above with center O, what is the length of in the Data Sufficiency forum
“Since we know that minor arc BC is a 60* arc (corresponding to a 30* interior angle), then we know that it makes up 1/6 of the circumference of the circle. If we can find the circumference, we''ll know the value of arc BC. (1) diameter AC = 24 Given the diameter, we''ll be able to find the value ...”
August 7, 2018
ceilidh.erickson posted a reply to Is the tens digit of a two digit integer k divisible by 3? in the Data Sufficiency forum
“Rephrased question: is the tens digit of k a 3, 6, or 9? Test values with the statement to try to prove insufficiency: (1) k - 5 is a multiple of 3 This tells us that k is 5 more than some multiple of 3. Test some 2-digit multiples of 3: Case 1: 3x = 27 --> k = 32. Is the tens digit ...”
August 7, 2018
ceilidh.erickson posted a reply to How I got a 740 (Q50 V40) !!! in the I just Beat The GMAT! forum
“Congratulations on the fantastic score! I''m so glad that you found the Manhattan Prep materials helpful. Best of luck on the applications!”
August 7, 2018
ceilidh.erickson posted a reply to GMAT OG 2019 Linda Kerber argued in the mid-1980s in the Reading Comprehension forum
“Poster: please double-check your question numbers and your OAs. You list questions 448-452, but give answers for 449-453. At least one of the OAs you listed is incorrect.”
August 7, 2018
ceilidh.erickson posted a reply to GMAT Official Guide 2019 Boreal owls range over a much in the Critical Reasoning forum
“With BOLDFACE questions in CR, you need to determine the following: - what is the author''s position? (or someone else''s position presented by the author)? - what is given in support of that position? - are there opposing viewpoints presented? - is each statement and OPINION or a FACT? ...”
August 7, 2018
ceilidh.erickson posted a reply to OG VR 19: Since 1992, in an attempt to build in the Sentence Correction forum
“This question is testing PRONOUNS and MEANING. (A) them - there is pronoun ambiguity. Because "them" could refer to "state officials" or "rivers" (or possibly even "salmon"), we should use a noun rather than a pronoun. (B) the river - since ...”
August 7, 2018
ceilidh.erickson posted a reply to OG VR 18 : Long overshadowed by the Maya and Aztec in the Sentence Correction forum
“This question is testing MODIFIERS and MEANING. Whenever a sentence begins with a participial modifier such as "Long overshadowed by the Maya and Aztec civilizations...", that must be followed by the SUBJECT being modified. The thing long overshadowed by other civilizations is the ...”
August 7, 2018
GMATGuruNY posted a reply to If the speed of X meters per second is equivalent to the in the Problem Solving forum
“Plug in for x a value that is easy to convert from meters to kilometers. Let x = 1000 meters per second. Since 1000 meters = 1 kilometer, this rate = 1 kilometer per second. Since there are 3600 seconds in an hour, 1 kilometer per second = 3600 kilometers per hour. Thus, y = 3600. This is ...”
August 7, 2018
GMATGuruNY posted a reply to If the average (arithmetic mean) of four different numbers in the Data Sufficiency forum
“Sum of the 4 numbers = (quantity)(average) = 4*30 = 120. Statement 1: Case 1: The four numbers are 32, 31, 30, 27 In this case, two of the numbers are greater than 30. Case 2: The four numbers are 33, 32, 31, 24 In this case, three of the numbers are greater than 30. INSUFFICENT. ...”
August 7, 2018
GMATGuruNY posted a reply to During a one day sale, a store sold each sweater of a in the Data Sufficiency forum
“Statement 1: Case 1: 1 sweater is sold for $270 Case 2: 3 sweaters are sold for $90 each Since the number of sweaters sold can be different values, INSUFFICIENT. Statement 2: Since the $30 markup is 1/2 the cost of each sweater, the cost of each sweater = 60. Thus, the selling price of ...”
August 7, 2018
GMATGuruNY posted a reply to Which of the following CANNOT be the least common multiple in the Problem Solving forum
“If x and y are equal, then their LCM = x = y. Thus, x+y can be the LCM of x and y only if x and y are NOT equal. If x+y is the LCM of x and y, then dividing x+y by x or y must yield an INTEGER. If we divide x+y by x. we get: (x+y)/x = x/x + y/x = 1 + y/x. The expression in blue will be an ...”
August 6, 2018
GMATGuruNY posted a reply to Which of the following CANNOT be the least common multiple in the Problem Solving forum
“Neither x-y nor x+y can be the LCM of x and y. What is the source of this problem?”
August 5, 2018
GMATGuruNY posted a reply to IF N=5^5*10^10*15^15*20^20*25^25*30^30*35^35*40^40*45^45*50^ in the Problem Solving forum
“This problem is about TRAILING 0''s: the number of 0''s at the end of a large product. Since 10=2*5, EVERY COMBINATION OF 2*5 contained within the prime-factorization of N will yield a 0 at the end of the integer representation of N.. N=5⁵ * 10¹⁰ * 15¹⁵ * 20²⁰ * 25²⁵ * 30³⁰ ...”
August 5, 2018
GMATGuruNY posted a reply to A contractor combined x tons of a gravel mixture that in the Data Sufficiency forum
“x = 10% gravel y = 2% gravel. z = the MIXTURE of x and y = 5% gravel. To determine the required ratio of x to y, use ALLIGATION -- a very efficient way to handle MIXTURE PROBLEMS. Step 1: Plot the 3 percentages on a number line, with the percentages for x and y on the ends and the ...”
August 4, 2018
GMATGuruNY posted a reply to In the figure, angle C and angle M are right angles, and KL in the Data Sufficiency forum
“Statement 1: Since ∠C=∠M=90 and ∠ABC=∠KLM, the remaining two angles are also equal: ∠BAC=∠LKM. Triangles with the same combination of angles are SIMILAR. In similar triangles, corresponding sides in the SAME RATIO. Here, AB and KL are corresponding sides, since each is a ...”
August 4, 2018
GMATGuruNY posted a reply to In the figure, angle C and angle M are right angles, and KL in the Data Sufficiency forum
“Statement 1: Since ∠C=∠M=90 and ∠ABC=∠KLM, the remaining two angles are also equal: ∠BAC=∠LKM. Triangles with the same combination of angles are SIMILAR. In similar triangles, corresponding sides in the SAME RATIO. Here, AB and KL are corresponding sides, since each is a ...”
August 4, 2018
GMATGuruNY posted a reply to A certain junior class has 1,000 students and a certain in the Problem Solving forum
“P(sibling pair) = (total number of sibling pairs)/(total number of possible pairs). Total number of possible pairs: There are 1000 juniors and 800 seniors. Total number of ways to combine 1 junior with 1 senior = 1000*800 = 800,000. Total number of sibling pairs = 60. Thus: ...”
August 4, 2018
GMATGuruNY posted a reply to A software company contracted its sister network in the Data Sufficiency forum
“Statement 1: Case 1: T= 20,000 and L = 10,000, In this case, L/T = 10,000/20,000 = 1/2. Case 2: T = 30,000 and L = 20,000 In this case, L/T = 20,000/30,000 = 2/3. Since L/T can be different values, INSUFFICIENT. Statement 2: In other words, the equipment charge alone is equal to 5/6 of the ...”
August 4, 2018
GMATGuruNY posted a reply to What is the hundredths digit of th decimal Z? in the Data Sufficiency forum
“Statement 1: 100z = 0.2, 1.2, 2.2... Dividing every value by 100, we get the following options for z: z = 0.002, 0.012, 0.022... Since the hundredth digit of z can be different values, INSUFFICIENT. Every value in the blue list above also satisfies Statement 2. Thus -- even when the ...”
August 3, 2018
ceilidh.erickson posted a reply to Is |x| + |y| = 0 ? in the Problem Solving forum
“You''re completely right! Total goof from going too quickly. I''ve edited accordingly. The underlying idea hasn''t changed, though: if 2 unknowns are each twice the absolute value of the other, they must both be 0.”
August 2, 2018
GMATGuruNY posted a reply to speed and distance in the Data Sufficiency forum
“Regular day: Let r = the regular rate and t = the regular time, implying that the distance to the office = rt. Last Wednesday: Since Mr. David drives 25% faster -- 5/4 of his regular speed -- the rate = (5/4)r. Since Mr. David leaves 30 minutes late -- reducing the time by 30 minutes -- the ...”
August 2, 2018
GMATGuruNY posted a reply to sets in the Problem Solving forum
“To organize the data, use a DOUBLE-MATRIX. 10% of the people do not have a university diploma but have a job of their choice. The following matrix is yielded: https://s33.postimg.cc/ouzby26ln/matrix_diploma_job_1.png 40% people have a job of their choice. The following matrix is yielded: ...”
August 1, 2018
ceilidh.erickson posted a reply to Is |x| + |y| = 0 ? in the Problem Solving forum
“ABSOLUTE VALUE is the distance from 0, so it must always be greater than or equal to 0. For the sum of two absolute values |x| + |y| to equal zero, it must be the case that both are equal to zero. Target question: are both x and y equal to 0? (1) x + 2|y| = 0 Test values to try to get ...”
August 1, 2018
ceilidh.erickson posted a reply to GMAT Official guide-CR question in the The 60-Day GMAT Study Guide forum
“This questions is #583 in OG2018 (edits in red above). If we''re asked for an ALTERNATIVE EXPLANATION, we''re looking for something that gives a causal connection. Given: - people who bought tickets to individual plays had a no-show rate of less than 1 percent - those who paid in advance ...”
August 1, 2018
ceilidh.erickson posted a reply to What percentage of the practice problems should I get right? in the The 60-Day GMAT Study Guide forum
“Because the GMAT is adaptive, it''s not a question of how many questions you get right; it''s a question of which ones you get right. If you''re getting all of the easy and medium questions right, you''ll be getting higher-level questions and end up with a high-level score. If you''re missing ...”
August 1, 2018
ceilidh.erickson posted a reply to All intelligent people are nearsighted. I am very in the Critical Reasoning forum
“This is not a GMAT-like question. What is the source of this question?”
August 1, 2018
ceilidh.erickson posted a reply to If (x+y)/z = -2, is x positive? in the Data Sufficiency forum
“First, REPHRASE the question to determine what kind of information we need for sufficiency. If a fraction is equal to a negative number, then either then numerator is negative and the denominator positive, or vice versa. In order for x to be positive, the entire numerator (x + y) could be ...”
August 1, 2018
ceilidh.erickson posted a reply to American "heirloom" tomatoes, once common varietie in the Critical Reasoning forum
“Since you didn''t put any statements in boldface, it''s impossible to answer this question.”
August 1, 2018
GMATGuruNY posted a reply to Speed/time in the Problem Solving forum
“Since Deb drives for 3/4 of an hour at a rate of 40 mph, the driving distance to work = rt = (40)(3/4) = 30 miles. Since the biking distance is 20% less than the driving distance, the biking distance = 30 - (1/5)(30) = 24 miles. To guarantee an on-time arrival at even the least possible biking ...”
August 1, 2018
GMATGuruNY posted a reply to Mr. Alex usually starts at 9:00am and reaches his office in the Data Sufficiency forum
“20t feet. Statement 1: Since Mr. Alex leaves 20 minutes early last Monday -- giving himself an additional 20 minutes -- the time last Monday = t + 20 minutes. Since Mr. Alex drives 20% slower, the rate last Monday = 20 - (20% of 20) = 16 feet per minute. Thus, the distance traveled last Monday ...”
July 31, 2018
GMATGuruNY posted a reply to What is the median of 10 numbers? in the Data Sufficiency forum
“Statement 1: Case 1: X, X, X, X, 10, 10, X, X, X, X Here, the 6 blue values are all less than or equal to 10. In this case, the median = (10+10)/2 = 10 Case 2: X, X, X, X, 8, 10, X, X, X, X Here, the 6 red values are all less than or equal to 10. In this case, the median = (8+10)/2 = 9. Since ...”
July 31, 2018
ceilidh.erickson posted a reply to A bakery sells white bread for certain price and rye bread in the Data Sufficiency forum
“(Let''s ignore the non-idiomatic pluralization "breads" rather than "loaves of bread.")... Let: w = the price of one loaf of white bread r = the price of one loaf of rye bread Question: 2w + 3r = ? Keep in mind that we do not necessarily need to find the values of w and ...”
July 30, 2018
ceilidh.erickson posted a reply to If S is a data set of three numbers x, y and z, is the range in the Data Sufficiency forum
“You can solve this problem by testing numbers. (1) x – y < 1 This tell us that the distance between x and y is less than 1, but it gives us no information about z, so we can''t know anything about the range of the set. Insufficient. (2) y – z < 2 This tells us that the distance ...”
July 30, 2018
ceilidh.erickson posted a reply to GMATPrep Practice Exam #1 - What Does my Percentile Mean? in the GMAT Math forum
“IGNORE PERCENTILES!! They do not accurately reflect anything about your ability, as they shift over time. You should be focused only on your subscore from 6-51. More information on that here: https://www.manhattanprep.com/gmat/blog/2016/02/11/heres-why-you-may-be-misinterpreting-your-gmat-score/ ...”
July 30, 2018
GMATGuruNY posted a reply to George and Steven drive separate cars the same distance from in the Data Sufficiency forum
“Statement 1: Here, Steven''s time can be any nonnegative value. INSUFFICIENT. Statement 2: Rate and time have a RECIPROCAL RELATIONSHIP. Since George''s speed in 2/3 Steven''s speed, George''s time is 3/2 Steven''s time. Since George''s time is 3.5 hours, we get: 3.5 = (3/2)t 7 = 3t 7/3 = ...”
July 30, 2018
GMATGuruNY posted a reply to If m=-1 and n = 1^2 + 2^2 + … + 10^2, what is the value of in the Problem Solving forum
“(-1)^odd = -1. (-1)^even = 1. The exponents for the expression in blue are 4 consecutive integers -- n, n+1, n+2, n+3 -- implying that two of the exponents will be ODD, while the other two will be EVEN. Thus, two of the terms in the blue expression must be equal to -1, while the other two must be ...”
July 30, 2018
GMATGuruNY posted a reply to A box of balls originally contained 2 blue balls for every in the Problem Solving forum
“A box of balls originally contained 2 blue balls for every red ball. Let the number of red balls = x and the number blue balls = 2x, implying that the total number of balls = x+2x = 3x. After 12 red balls were added to the box, the ratio of red balls to blue balls became 5 to 2. Since 12 red ...”
July 30, 2018
GMATGuruNY posted a reply to What is the probability of getting only 1 head in a single in the Problem Solving forum
“P(HTT) = 1/2 * 1/2 * 1/2 = 1/8. Since a good outcome will be yielded if H is first, second or third, we multiply by 3: 1/8 * 3 = 3/8. The correct answer is B.”
July 30, 2018
GMATGuruNY posted a reply to Let abcd be a general four-digit number. How many odd four in the Problem Solving forum
“Condition: a*b = integer cd Since abcd must be odd and composed of 4 distinct digits, we get the following options for integer cd: 21, 31, 41, 51, 61, 71, 81, 91 13, 23, 43, 53, 63, 73, 83, 93 15, 25, 35, 45, 65, 75, 85, 95 17, 27, 37, 47, 57, 67, 87, 97 19, 29, 39, 49, 59, 69, 79, 89 ...”
July 29, 2018
GMATGuruNY posted a reply to Two thirds of the roads from A to B are at least 5 miles in the Problem Solving forum
“P(at least one of the 2 selected roads is at least 5 miles long) = 1 - P(neither of the 2 selected roads is at least 5 miles long) From A to B: Since 2/3 of the roads are at least 5 miles long, 1/3 are not. Thus, the probability of selecting a road that is not at least 5 miles long = 1/3. ...”
July 29, 2018
GMATGuruNY posted a reply to If s is the sum of all integers from 1 to 30, inclusive, in the Problem Solving forum
“To calculate the sum of an integer''s positive factors: 1. Prime-factorize the integer 2. Write the prime-factorization in the form (a^p)(b^q)(c^r)... 3. Sum of the factors = (1+a¹+ a²+a³+...+a^p)(1+b¹+ b²+b³+...+b^q)(1+c¹+ c²+c³+...+c^r)... What is the sum of the positive factors of ...”
July 29, 2018
GMATGuruNY posted a reply to In 1990 850 million movie tickets were sold in the United St in the Data Sufficiency forum
“The statement in red does not accurately reflect the information in Statement 2. Statement 2: People under the age of 20 spent $2.2 billion MORE on movie tickets than did people over the age of 50. Here, the total amount spent by people under the age of 20 ≠ $2.2 billion. The usage of MORE ...”
July 28, 2018
GMATGuruNY posted a reply to If a sequence of positive odd integers has six terms contain in the Problem Solving forum
“This problem is invalid. Since the only conditions are that six terms must be positive and odd and have a total of 13 digits, an infinite number of cases are possible. Here are two options: 11, 13, 15, 17, 19, 101 13, 11, 15, 17, 19, 101 Since the sequence does not have to be ascending, any of ...”
July 28, 2018
GMATGuruNY posted a reply to If the sum of 3 consecutive integers is 54, then what is the in the Problem Solving forum
“Average of the 3 consecutive integers = sum/quantity = 54/3 = 18. For any set of consecutive integers, average = median. Thus, the median of the 3 integers = 18, implying that the 3 integers are 17, 18, and 19. Product of the smallest and largest = 17*19 = integer with a units digit of 3. The ...”
July 28, 2018
GMATGuruNY posted a reply to What is the sum of the digits of two-digit positive integer in the Data Sufficiency forum
“Statement 1: Let M = 10T + U, where T = the tens digit and U = the units digit. When the digits are reversed, we get: 10U + T. Since the reversed integer is 27 more than M, we get: (10U + T) - (10T + U) = 27 9U - 9T = 27 9(U-T) = 27 U-T = 3. U = T+3 The resulting equation indicates ...”
July 28, 2018
GMATGuruNY posted a reply to During a 40-mile trip, Marla traveled at an average speed of in the Data Sufficiency forum
“Time and rate are RECIPROCALS. x = the REGULAR speed. 1.25x = the FASTER speed. 1.25x = (125/100)x = (5/4)x. 5/4 the rate implies 4/5 the time. Thus: The time needed at the FASTER speed is equal to 4/5 the time needed at the REGULAR speed. The question stems asks for the following ratio: ...”
July 28, 2018
July 27, 2018
GMATGuruNY posted a reply to A jar contains 12 marbles consisting of an equal number of in the Problem Solving forum
“For only 2 colors to remain after 4 marbles have been removed, the 4 selected marbles must be of the same color. The first selected marble can be of ANY COLOR. A good outcome will be yielded if the second, third and fourth marbles are of the SAME COLOR as the first. P(2nd marble is of the same ...”
July 27, 2018