# sandhu21

Brent@GMATPrepNow posted a reply to If a is a positive integer and 81 divided by a in the Data Sufficiency forum
“Target question: What is the value of a? Given: 81 divided by a results in a remainder of 1 In other words, 81 is 1 greater than some multiple of a This means that 80 is some multiple of a Another way to say this is: a is a divisor of 80 The divisors of 80 are: 1, 2, 4, 5, 8, 10, 16, ...”
Yesterday
Brent@GMATPrepNow posted a reply to Set A = {2, 3, 4, 5}, and set B = {4, 5, 6, 7, 8}. If P = th in the Problem Solving forum
“Let''s list and count all possible outcomes. Possible products when 2 is selected from set A: 8, 10, 12, 14, 16 Possible products when 3 is selected from set A: 12, 15, 18, 21, 24 Possible products when 4 is selected from set A: 16, 20, 24, 28, 32 Possible products when 5 is selected from set ...”
Yesterday
Brent@GMATPrepNow posted a reply to If Sam were twice as old as he is, he would be 40 years in the Problem Solving forum
“Jim is 10 years younger than Sam Let x = Sam''s PRESENT age So, x - 10 = Jim''s PRESENT age If Sam were twice as old as he is, he would be 40 years older than Jim. TWICE Sam''s age = 2x So, we can write: 2x = (x - 10) + 40 Simplify: 2x = x + 30 Solve: x = 30 Answer: B Cheers, Brent”
Yesterday
Brent@GMATPrepNow posted a reply to One night a certain hotel rented 3/4 of its rooms, including in the Problem Solving forum
“This question is a great candidate for the Double Matrix method, whichcan be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of motel rooms, and the two characteristics are: - air conditioning or no air ...”
Yesterday
Brent@GMATPrepNow posted a reply to In a certain pet shop, 1/3 of the pets are dogs and 1/5 of in the Data Sufficiency forum
“Target question: How many of the pets are dogs? Given: 1/3 of pets are dogs & 1/5 of pets are birds Let T = TOTAL number of pets. So, T/3 = number of dogs And T/5 = number of birds Statement 1: There are 30 birds at the pet shop So, T/5 = 30 This means that T = 150, which ...”
Yesterday
Brent@GMATPrepNow posted a reply to Is x > y? (1) -4x + 2y < y - 3x (2) wx > wy in the Data Sufficiency forum
“Target question: Is x > y? Statement 1: -4x + 2y < y - 3x Add 4x to both sides to get: 2y < y + x Subtract y from both sides to get: y < x Perfect, the answer to the target question is YES, x IS greater than y Since we can answer the target question with certainty, statement 1 ...”
Yesterday
Brent@GMATPrepNow posted a reply to At a certain fruit stand, the price of each apple is 40 cent in the Problem Solving forum
“It turns out that the cost per apple is irrelevant. Here''s why: The average (arithmetic mean) price of the 10 pieces of fruit is 56 cents So, (total value of all 10 pieces of fruit)/10 = 56 cents This means, total value of all 10 pieces of fruit = 560 cents How many oranges must Mary put ...”
Yesterday
Brent@GMATPrepNow posted a reply to A set consists of 5 distinct positive integers a, b, c, d, e in the Problem Solving forum
“The mean of all 5 numbers is 8.8 (a + b + c + d + e)/5 = 8.8 Multiply both sides by 5 to get: a + b + c + d + e = 44 The sum of a, c and e is 24 (a + c + e) = 24 So, take a + b + c + d + e = 44 and rewrite as: (a + c + e) + b + d = 44 We get: (24) + b + d = 44 So, b + d = 20 b is the ...”
Yesterday
Brent@GMATPrepNow posted a reply to If x and y are consecutive integers such that x < y and x in the GMAT Math forum
“Oops - pressed the wrong button. As you were! Brent”
Yesterday
Brent@GMATPrepNow posted a reply to If 3 years ago Jennifer was 22 years old, how old is Carmen in the Data Sufficiency forum
“Target question: How old is Carmen now? Given: 3 years ago Jennifer was 22 years old So, Jennifer''s PRESENT age is 25 Statement 1: 10 years ago, Carmen was twice as old as Jennifer. If Jennifer''s PRESENT age is 25, then Jennifer''s age 10 YEARS AGO was 15 This means Carmen''s age 10 ...”
Yesterday
Brent@GMATPrepNow posted a reply to In a barrel full of apples, 45% of the apples weigh more in the Problem Solving forum
“No takers? Let''s say there are 100 apples in the barrel. 45% of the apples weigh MORE THAN 81 grams This means 55% of the apples weigh LESS THAN OR EQUAL to 81 grams In other words, 55 apples weigh LESS THAN OR EQUAL to 81 grams 81% of the apples weigh LESS THAN 145 grams This means 19% ...”
January 18, 2019
Brent@GMATPrepNow posted a reply to Passing the 30-question third section in the Data Sufficiency forum
“ Given: A dental licensure exam requires a 75% minimum score in order to pass each section Target question: Did Jennifer pass the 30-question third section? 75% of 30 = 22.5 So, in order to get at least 75% in the 3rd section, Jennifer must correctly answer 23 or more questions in the 3rd ...”
January 18, 2019
Brent@GMATPrepNow posted a reply to 32 teams compete in the World Cup of Soccer. They are divid in the Problem Solving forum
“Perfect approach! ASIDE: We have 4 teams, and 2 teams play a game. So, the number of games played = the number of different ways to select 2 of the 4 teams = 4C2 = 6 Cheers, Brent”
January 18, 2019
Brent@GMATPrepNow posted a reply to Does (a – 2)(b + 4) = 8? in the GMAT Math forum
“Target question: Does (a – 2)(b + 4) = 8? This is a good candidate for rephrasing the target question. When I SCAN the statements, I see that statement 1 has the term ab. This suggests to me that we might benefit from EXPANDING the expression, since that will result in an ab term. Take: (a ...”
January 18, 2019
Brent@GMATPrepNow posted a reply to A fair die has sides labeled with 1, 2, 3, 4, 5, and 6 dots. in the GMAT Math forum
“We want P(select at least one 6) When it comes to probability questions involving "at least," it''s best to try using the complement. That is, P(Event A happening) = 1 - P(Event A not happening) So, here we get: P(getting at least one 6) = 1 - P(not getting at least one 6) What does ...”
January 18, 2019
Brent@GMATPrepNow posted a reply to If x and y are consecutive integers such that x < y and x in the GMAT Math forum
“GIVEN: x and y are consecutive integers such that x < y So, if x is ODD, then y is EVEN One option here is to replace the x''s and y''s with ODD and EVEN and apply the rules for ODDs and EVENs. Or we can just replace x and y with odd and even numbers. Let''s do that. Replace x with 1 ...”
January 18, 2019
Brent@GMATPrepNow posted a reply to is x > 0? in the GMAT Math forum
“Target question: Is x > 0 ? Statement 1: x – y > –8 This statement doesn''t feel sufficient, so I''ll TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 1 and y = 0. In this case, the answer to the target question is YES, x ...”
January 18, 2019
Brent@GMATPrepNow posted a reply to If x is an integer greater than 2, the function f(x) in the GMAT Math forum
“The key here is that f(51) is EQUAL to f(50) Here''s why: According to the definition of the function f, f(51) = (2)(4)(6). . . (48)(50), and f(50) = (2)(4)(6). . . (48)(50) So, f(51) - f(50) = (2)(4)(6). . . (48)(50) - (2)(4)(6). . . (48)(50) = 0 Answer: E Cheers, Brent”
January 18, 2019
Brent@GMATPrepNow posted a reply to What percentage of his bills did Stanley pay before their in the Data Sufficiency forum
“Target question: What percentage of his bills did Stanley pay before their due dates last month? This is a great candidate for rephrasing the target question. Aside: We have a free video with tips on rephrasing the target question: Let P = # of bills PAID before due date Let T = TOTAL # of ...”
January 17, 2019
Brent@GMATPrepNow posted a reply to Overlapping figures in the Problem Solving forum
“If the area of the square is 4, then each side has length 2 https://i.imgur.com/Ul16WsZ.png At this point, we have a special 30-60-90 right triangle. When we compare this blue triangle to the BASE 30-60-90 right triangle . . . https://i.imgur.com/vrYSacE.png . . . we see that the blue ...”
January 17, 2019
Brent@GMATPrepNow posted a new topic called Set A = {2, 3, 4, 5}, and set B = {4, 5, 6, 7, 8}. If P = th in the Problem Solving forum
“Set A = {2, 3, 4, 5}, and set B = {4, 5, 6, 7, 8}. If P = the product of one number chosen from set A and one number chosen from set B, how many DIFFERENT values of P are possible? A) 14 B) 15 C) 16 D) 18 E) 20 Answer: C Difficulty level: 600 - 650 Source: www.gmatprepnow.com”
January 17, 2019
Brent@GMATPrepNow posted a reply to If 20 Swiss Francs is enough to buy 9 notebooks in the Data Sufficiency forum
“Target question: Is 40 Swiss Francs enough to buy 12 notebooks and 12 pencils? This is a great candidate for rephrasing the target question. Let N = the cost of 1 notebook (in Swiss francs) Let P = the cost of 1 pencil (in Swiss francs) So, 12 notebooks cost 12N and 12 pencils cost 12P ...”
January 17, 2019
Brent@GMATPrepNow posted a reply to The speed of a boat is 5 times the speed at which a river fl in the Problem Solving forum
“Let x = the speed of the river (in miles per hour) So, 5x = the speed of the boat in (miles per hour) Let d = distance traveled (in miles) This means the boat''s speed going UPriver = 5x - x = 4x And the boat''s speed going DOWNriver = x + 5x = 6x time = distance/speed So, travel time ...”
January 17, 2019
Brent@GMATPrepNow posted a reply to If Jake loses 8 pounds, he will weigh twice as much as his s in the Problem Solving forum
“Here''s a solution that uses one variable. Let x = Jake''s present weight in pounds So, x - 8 = Jake''s hypothetical weight IF he were to lose 8 pounds If Jake loses 8 pounds, he will weigh twice as much as his sister. In other words, the sister weighs HALF as much as Jake''s hypothetical ...”
January 17, 2019
Brent@GMATPrepNow posted a reply to Three children, John, Paul, and Ringo, are playing a game. in the Problem Solving forum
“The main concept here is that all 3 children are equally likely to win this game (unless one of them possesses supernatural powers that allow him to know what numbers the other two boys will choose :-)) Also note that, if everything is random, the probability of winning by choosing the number 2 ...”
January 16, 2019
Brent@GMATPrepNow posted a new topic called In a barrel full of apples, 45% of the apples weigh more in the Problem Solving forum
“In a barrel full of apples, 45% of the apples weigh more than 81 grams, and 81% of the apples weigh less than 145 grams. What percent of the apples in the barrel weigh more than 81 grams but less than 145 grams? A) 16 B) 18 C) 26 D) 32 E) 36 Answer: C Difficulty level: 600 - 650 Source: ...”
January 16, 2019
Brent@GMATPrepNow posted a reply to What is the surface area of the solid right circular in the Problem Solving forum
“Given: radius = 3 Height = 10 Surface area of cylinder = 2πr² + 2πrh = 2π(3²) + 2π(3)(10) = 18π + 60π = 78π Answer: D Cheers, Brent”
January 16, 2019
Brent@GMATPrepNow posted a reply to Three children, John, Paul, and Ringo, are playing a game. in the Problem Solving forum
“This is one of my all-time favorite questions!! The main concept here is that all 3 children are equally likely to win this game (unless one of them possesses supernatural powers that allow him to know what numbers the other two boys will choose :-)) Also note that, if everything is random, ...”
January 16, 2019
Brent@GMATPrepNow posted a reply to GMAT Official Guide 2019 From 2000 to 2003, the number in the Problem Solving forum
“From 2000 to 2003, the number of employees at a certain company increased by a factor of 1/4 Let x = the number of employees in 2000 So, the number of employees in 2003 = x + (1/4)x = (5/4)x From 2003 to 2006, the number of employees at this company decreased by a factor of 1/3 (5/4)x = the ...”
January 16, 2019
Brent@GMATPrepNow posted a reply to The usual price of a bagel was reduced during a sale. How mu in the Data Sufficiency forum
“Target question: How much money could be saved by purchasing 10 bagels at the sale price rather than at the usual price? Statement 1: The usual price for a bagel is $0.50 per bagel. Since there''s no information about the SALE price, there''s no way to calculate the amount saved. Since we ...” January 16, 2019 Brent@GMATPrepNow posted a reply to Henry eats X scones in X percent of the time it takes Rachel in the Problem Solving forum “Let''s use the INPUT-OUTPUT approach. Let''s assign some values of X and Y so that they satisfy the information in the question. Let X = 25. This means Henry eats 25 scones in 25 percent of the time it takes Rachel to eat Y scones Let Y = 100. This means Henry eats 25 scones in 25 percent of ...” January 15, 2019 Brent@GMATPrepNow posted a reply to Roger wants to arrange three of his five books on his in the Problem Solving forum “I''m not crazy about this question. The official answer suggests that, although 2 books are DUPLICATES, they''re still considered DIFFERENT. Here''s what I mean: Let''s let D and d represent the two duplicate books. Let, A, B and C represent the other three books. The official answer ...” January 15, 2019 Brent@GMATPrepNow posted a reply to The three-digit positive integer n can be written as ABC, in in the Data Sufficiency forum “IMPORTANT point: The VALUE of a 3-digit integer xyz is 100x + 10y + z Example: 723 = (7)(100) + (2)(10) + 3 Target question: What is the remainder when n is divided by 37? Statement 1: A + B/10 + C/100 = B + C/10 + A/100 Multiply both sides by 100 to get: 100A + 10B + C = 100B + 10C + ...” January 15, 2019 ceilidh.erickson posted a reply to GMATPaper : As measured by the Commerce in the Sentence Correction forum “Hm, I''m inclined to think that the sentence would NOT work as you suggested: ... corporate profits peaked in the fourth quarter of 1988 but they have slipped since then The word "peaked" already implies that it was a high point, naturally followed by lower values. The contrast word ...” January 15, 2019 ceilidh.erickson posted a reply to At the end of the first quarter, the share price of a in the Problem Solving forum “Calculating the correct answer isn''t difficult, as Brent demonstrated. However, savvy GMAT test takers will always try to use logic to eliminate answer choices before they even start calculating! The student who isn''t reading carefully might think "up 20%... then up 50%... that''s a ...” January 15, 2019 ceilidh.erickson posted a reply to In a certain bathtub, both the hot and cold water fixtures in the Problem Solving forum “We can easily use logic to get the correct answer, without doing any calculations. In WORK rate problems, when two machines / faucets / people, etc, work together, a) they work at the SUM of their respective rates, and b) the time that it takes them to complete the task together is LESS than ...” January 15, 2019 ceilidh.erickson posted a reply to Every day in the morning Ross cycles for 2 hours. He always in the Problem Solving forum “You could also avoid calculation and easily estimate your way to the correct answer to save time on this problem. As Mitch demonstrated, 1 mile per 12 min --> 5 miles per hr for the first part of the trip. If Ross rides at half the speed for the return trip, then the overall average speed ...” January 15, 2019 ceilidh.erickson posted a reply to In a 200 member association consisting of men and women, exa in the Problem Solving forum “OP, are you sure this is an OG question? Which edition of the OG did you get this problem from? It''s not in any edition I own. A google search yields only 1 post from gmatclub, and 3 posts on this forum - all posted by you in the last month. The wording of this problem does not sound like an OG ...” January 15, 2019 Brent@GMATPrepNow posted a reply to If x, y are integers, is x^2+x+y an odd integer? in the Data Sufficiency forum “ Given: x and y are integers Target question: Is x² + x + y an odd integer? This is a good candidate for rephrasing the target question. Take x² + x + y and factor the first two terms to get: x(x + 1) + y Notice that x and x+1 are CONSECUTIVE INTEGERS, which means one value is ODD and ...” January 15, 2019 Brent@GMATPrepNow posted a reply to In a 200 member association consisting of men and women, exa in the Problem Solving forum “In order to minimize the number of homeowners, we must MAXIMIZE the number of men in the group, since the proportion of male homeowners (20%) is less than the proportion of female homeowners (25%) So, let''s see what happens if there are 199 men and 1 woman. If 20% (aka 1/5) of the men are ...” January 15, 2019 Brent@GMATPrepNow posted a reply to Three machines have equal constant work rates. It takes h + in the Problem Solving forum “ It takes h + 3 hours to produce 360 toys when 2 machines work together So, during those h + 3 hours, EACH machine makes 180 toys So, ONE machine can produce 180 toys in h + 3 hours rate = output/time So, we can write: rate of ONE machine = 180/(h + 3) It takes h hours to produce 360 toys ...” January 14, 2019 ceilidh.erickson posted a reply to Admissions cosultants in the The Application Process forum “It looks like BTG has added that feature since you posted: https://reviews.beatthegmat.com/ You should also check out Poets & Quants: https://poetsandquants.com/2018/04/27/best-mba-admission-consultants/ https://poetsandquants.com/consultants/” January 12, 2019 ceilidh.erickson posted a reply to 60Day GMAT PREP Question in the GMAT Strategy forum “Studying without reviewing is almost entirely useless - it''s like trying to collect water with a sieve. Or trying to collect tennis balls like this: https://www.youtube.com/watch?v=L5C8rnpAbIs It is absolutely essential that you make reviewing a large part of your process. In fact, you should ...” January 12, 2019 ceilidh.erickson posted a reply to Post-First Exam: What are my next steps? in the GMAT Strategy forum “You mention that you''ve read most of the guides and done practice problems. There are a few things you haven''t mentioned, though: - how were you doing those practice problems? Were you doing them timed, and carefully tracking your errors? - do you have a solid understanding of test strategy as ...” January 12, 2019 ceilidh.erickson posted a reply to Over the last five years, demand for hotel rooms in Cenopoli in the Critical Reasoning forum “If we want 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: - demand for hotel rooms in Cenopolis has increased significantly - so has the average price Cenopolis hotels ...” January 12, 2019 ceilidh.erickson posted a reply to Bluegrass musician Bill Monroe, whose repertory, views on in the Sentence Correction forum “The reason "that of" redundant is that in the non-underlined portion we have "his own," which is already possessive. (This is similar to saying "my music of mine.") Since we can''t change that non-underlined part, none of the fixes you suggested would work for this ...” January 12, 2019 ceilidh.erickson posted a reply to People with high blood pressure are generally more nervous a in the Critical Reasoning forum “For more on how the GMAT tests correlation v. causation, see: https://www.beatthegmat.com/male-bowerbirds-construct-elaborately-decorated-nests-or-t303937.html#818930 https://www.beatthegmat.com/veritas-cat-question-doubt-t300364.html#808487 ...” January 12, 2019 ceilidh.erickson posted a reply to People with high blood pressure are generally more nervous a in the Critical Reasoning forum “This argument demonstrates a very common logical flaw: CORRELATION v. CAUSATION. We''re given that "people with high blood pressure are generally more nervous and anxious than people who do not have high blood pressure." In other words, these two phenomena tend to occur together. ...” January 12, 2019 ceilidh.erickson posted a reply to Researchers have found entombed in Burmese amber a 102-milli in the Sentence Correction forum “This question is primarily testing MODIFIERS and LOGICAL PARALLELISM. Researchers have found entombed in Burmese amber a 102-million-year-old tick grasping the feather of a Velociraptor, providing the first direct evidence that the tiny pests drank dinosaur blood. (A) entombed in Burmese ...” January 12, 2019 ceilidh.erickson posted a reply to A new commercial radio station in Greenfield plans to play s in the Critical Reasoning forum “The chain of logic in this argument is as follows: play songs that were popular hits fifteen to twenty-five years ago --> attract an audience made up mainly of people between thirty-five and forty-five years old --> strong market appeal to advertisers. This argument is relying on the ...” January 12, 2019 ceilidh.erickson posted a reply to I took the GMAT today in the GMAT Strategy forum “I''m so sorry to hear that. But you''re not alone - this test is hard, and many people don''t get the score they''re hoping for on the first try. Here are some possible explanations for why your score went down: 1. You were emphasizing content over strategy (esp timing strategy) You said ...” January 12, 2019 Brent@GMATPrepNow posted a reply to There is a total of 120 marbles in a box, each of which is in the Problem Solving forum “...the probability that it So, 1/4 of the 120 marbles are white. In other words, there are 30 white marbles. ...the probability that it So, 1/3 of the 120 marbles are green . In other words, there are 40 green marbles. Altogether, there are 70 marbles that are EITHER white or green. ...” January 12, 2019 Brent@GMATPrepNow posted a reply to To furnish a room in model home, an interior decorator is to in the Problem Solving forum “Total # of combinations = (# of ways to select 2 chairs)(# of ways to select 2 tables) So, 150 = (# of ways to select 2 chairs)(# of ways to select 2 tables) # of ways to select 2 chairs 5 tables, choose 2 of them. Since the order of the selected chairs does not matter, we can use ...” January 11, 2019 Brent@GMATPrepNow posted a reply to At a certain fruit stand, the price of each apple is 40 in the Problem Solving forum “It turns out that the cost per apple is irrelevant. Here''s why: The average (arithmetic mean) price of the 10 pieces of fruit is 56 cents So, (total value of all 10 pieces of fruit)/10 = 56 cents This means, total value of all 10 pieces of fruit = 560 cents How many oranges must Mary put ...” January 11, 2019 Brent@GMATPrepNow posted a reply to A librarian has a set of ten books, including four different in the Problem Solving forum “Take the task of arranging the 10 books and break it into stages. Stage 1: Arrange the 4 books about Abe Lincoln in a row We can arrange n objects in n! ways. So, we can arrange the 4 books in 4! ways IMPORTANT: Now we''ll "glue" the 4 Abe Lincoln books together to form 1 SUPER ...” January 11, 2019 Brent@GMATPrepNow posted a reply to By what percent is 25 greater than 15? in the Problem Solving forum “An alternative approach is to test the answer choices First, however, we can eliminate some answer choices by first testing an easy value: 50% Is 25 50% greater than 15? Well, 50% of 15 = 7.5 So, 50% greater than 15 = 15 + 7.5 = 22.5 22.5 is too small (we need to get 25), so we need a ...” January 11, 2019 Brent@GMATPrepNow posted a reply to The price of a phone call consists of a standard connection in the Problem Solving forum “Let C = price of connection fee Let M = the price PER MINUTE A 10-minute call costs$2.90 We can write: C + 10M = 2.90 A 16-minute call costs $4.40. We can write: C + 16M = 4.40 How much does a 13-minute call cost? So far, we have: C + 10M = 2.90 C + 16M = 4.40 ONE (slower) ...” January 10, 2019 Brent@GMATPrepNow posted a reply to At the end of the first quarter, the share price of a in the Problem Solving forum “Let$100 = share price at the beginning of the year At the end of the first quarter, the share price of a certain mutual fund was 20 percent higher than it was at the beginning of the year. So, $120 = share price at the end of the first quarter At the end of the second quarter, the share ...” January 10, 2019 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Data Sufficiency Video #1: Introduction to GMAT Data Sufficiency Video: https://www.youtube.com/watch?v=3MaEqnSnK-s Cheers, Brent” January 10, 2019 Brent@GMATPrepNow posted a reply to 17^27 has a units digit of: in the Problem Solving forum “Look for a pattern 17^1 = 17 17^2 = (17)(17) = ---9 17^3 = (17)(17^2) = (17)(---9) = ----3 17^4 = (17)(17^3) = (17)(---3) = ----1 17^5 = (17)(17^4) = (17)(---1) = ----7 NOTICE that we''re back to where we started. 17^5 has units digit 7, and 17^1 has units digit 7 So, at this point, ...” January 10, 2019 Brent@GMATPrepNow posted a reply to The water from one outlet, flowing at a constant rate, can f in the Problem Solving forum “One approach is to assign a NICE NUMBER to the volume of the swimming pool. This number will work well with the two pieces of information (fill pool in 9 hours and fill pool in 5 hours). So, let''s say that the volume of the pool is 45 gallons. The water from one outlet, flowing at a constant ...” January 9, 2019 Brent@GMATPrepNow posted a reply to If x and y are positive, is x > y? in the Data Sufficiency forum “Target question: Is x > y? This is a good candidate for rephrasing the target question. Since y is POSITIVE, we can safely take the inequality x > y and divide both sides by y to get: x/y > 1 REPHRASED target question: Is x/y > 1? Aside: Here’s a video with tips on rephrasing ...” January 9, 2019 Brent@GMATPrepNow posted a reply to Emily keeps 12 different pairs of shoes (24 individual shoes in the Problem Solving forum “P(dog selects matching pair) = P(dog chooses ANY sock 1st AND 2nd sock matches the 1st sock) = P(dog chooses ANY sock 1st) x P(2nd sock matches the 1st sock) = 24/24 x 1/23 = 1/23 Answer: C Cheers, Brent” January 9, 2019 Brent@GMATPrepNow posted a reply to On a certain Monday, Carlos drove to work at an average in the Problem Solving forum “Average speed = (TOTAL distance)/TOTAL travel time)Carlos drove to work at an average speed of 50 miles per hour Time = distance/speed So, travel time TO work = d/50 hours Carlos drove home from work at an average speed of 70 miles per hour So, travel time FROM work = d/70 hours So, TOTAL ...” January 8, 2019 Brent@GMATPrepNow posted a reply to How many integers between in the Problem Solving forum “He spent 40% (of the$35) on chicken feed. 40% of $35 =$14. So, he spent $14 on chicken feed. He got a 20% discount on the chicken feed. In other words, he paid 80% of the original price. So, let C = original price of chicken feed. We can write 80% of C =$14 Or we can write 0.8C = $14 ...” January 8, 2019 Brent@GMATPrepNow posted a reply to On Monday, the opening price of a certain stock was$100 in the Problem Solving forum
“On Monday, the opening price of a certain stock was $100 per share and its closing price was$110 per share. On Tuesday the closing price of the stock was 10 percent less than its closing price on Monday, We can say that the stock LOST 10% of its value. OR we can say that the stock RETAINED 90% ...”
January 8, 2019
Brent@GMATPrepNow posted a reply to A department manager distributed a number of pens, pencils, in the Data Sufficiency forum
“Jay''s solution is great. I just wanted to mention that this question hinges largely on the fact that the number of pens, pencils, and pads that each staff member receives MUST HAVE INTEGER VALUES. So, for example, if statement 1 were different and statement 2 read "The manager ...”
January 8, 2019
Brent@GMATPrepNow posted a reply to In 1982 and 1983, Company B's operating expenses were $12.0 in the Problem Solving forum “The profit in 1982 = 15.6 - 12.0 =$3.6 million The profit in 1983 = 18.8 - 14.0 = $4.8 million Percent change = (100)(new - old)/old = (100)(4.8 - 3.6)/3.6 = (100)(1.2)/(3.6) = (100)(1/3) = 33 1/3% Answer: D Cheers, Brent” January 8, 2019 Brent@GMATPrepNow posted a reply to x is a positive integer, and the units digits of both (x+2)^ in the Problem Solving forum “Another approach is to test the answer choices A. If the units digit of x is 1, is it the case that units digits of both (x+2)² and (x-2)² is 9? Well, (x+2)² = (1+2)² = 9. Works! To test (x-2)², let''s let x = 11. We get: (11-2)² = 9² = 81. NO GOOD ELIMINATE A B. If the units digit ...” January 8, 2019 Brent@GMATPrepNow posted a reply to In 1991, the price of a house was 80% of its original price. in the Problem Solving forum “I''d typically assign a "nice" value to the original price, and then follow the steps that Mitch demonstrated. Alternatively, we can solve the question algebraically In 1991, the price of a house was 80% of its original price. Let x = the original price So, 0.8x = the 1991 price ...” January 7, 2019 Brent@GMATPrepNow posted a reply to If triangle ABC is an isosceles triangle, what is ∠ABC? in the Data Sufficiency forum “Target question: What is ∠ABC? Given: Triangle ABC is an isosceles triangle So, ∆ABC has 2 equal angles Statement 1: ∠CAB = 45 degrees Since ∆ABC has 2 equal angles, there are two possible triangles that satisfy statement 1: Case a: ∠CAB = 45, ∠BCA = 45 and ∠ABC = 90. ...” January 7, 2019 Brent@GMATPrepNow posted a reply to If f(a*b) = f(a) + f(b), what is the value of f(1)? in the Problem Solving forum “To generalize Mitch''s and Fabio''s solutions, notice that, as long as we can get f(1) involved in the process, we''ll arrive at answer choice C every time. Notice that k = 1*k Since f(a*b) = f(a) + f(b), we can write: f(1*k) = f(1) + f(k) Simplify: f(k) = f(1) + f(k) Subtract f(k) from both ...” January 7, 2019 Brent@GMATPrepNow posted a reply to After her birthday, Fiona had D dollars in gift money. in the Problem Solving forum “Another approach is to use algebra. After her birthday, Fiona had D dollars in gift money. She spent 3/5 of this on an electric skateboard. If Fiona SPENT 3/5 of D dollars, then 2/5 of D dollars REMAINED In other words, the amount remaining at the end of the day = 2D/5 dollars The next day, ...” January 6, 2019 Brent@GMATPrepNow posted a reply to After her birthday, Fiona had D dollars in gift money. in the Problem Solving forum “One option is to WORK BACKWARDS The next day, she spent 1/3 of what was left on a movie passcard, and then finally put the last$80 in the bank. If she spent 1/3 of her money on a movie passcard, then 2/3 of her money remained (which she put in the bank). This means 2/3 of her money = $80 We ...” January 6, 2019 Brent@GMATPrepNow posted a reply to A retailer sells only radios and clocks. If she currently ha in the Data Sufficiency forum “ Given: A retailer sells only radios and clocks, and she currently has 44 total items in inventory. Target question: How many radios are there in the inventory Statement 1: The retailer has more than 28 radios in inventory There are several scenarios that satisfy statement 1. Here are ...” January 6, 2019 Brent@GMATPrepNow posted a reply to Number Properties in the Data Sufficiency forum “The error is highlighted above in blue. if a>0 we will have the answer as YES is ALMOST true. The only time it''s not true is when a = 1 If a = 1, then the answer is NO. We can verify this using either the original inequality or the rephrased inequality. Take "Is a + 1/a > ...” January 6, 2019 Brent@GMATPrepNow posted a reply to A store sells erasers for 0.23$ per piece and pencil for in the Data Sufficiency forum
“This question illustrates a common trap on the GMAT. As Jay has shown, with statement 2, we''re able to write the equation 23x + 11y = 170 , and in high school we learned that, if we''re given 1 equation with 2 variables, we cannot find the value of either variable. However, if we restrict the ...”
January 5, 2019
Brent@GMATPrepNow posted a reply to A barn is enclosed in the shape of a 6-sided figure; all in the Data Sufficiency forum
“This Date Sufficiency question is almost identical to the following Problem Solving question, which requires us to find the actual area: http://www.beatthegmat.com/plz-explain-t270003.html Cheers, Brent”
January 5, 2019
Brent@GMATPrepNow posted a reply to In the rectangular coordinate system above, the area of in the Problem Solving forum
“Let''s draw a rectangle around the triangle (as shown below) and then subtract from the rectangle''s area (28) the areas of the 3 right triangles that surround the triangle in question. We get the following: http://s13.postimage.org/a47qx0j8j/triangle_in_coordinate_plane_2.jpg So, the area ...”
January 5, 2019
Brent@GMATPrepNow posted a reply to What is the perimeter of quadrilateral Q? in the Data Sufficiency forum
“Target question: What is the perimeter of quadrilateral Q? If we recognize that each statement alone is not sufficient, we can jump straight to...... Statements 1 and 2 combined There are several quadrilaterals satisfy BOTH statements. Here are two: Case a: Q is a rectangle with width 1 ...”
January 5, 2019
Brent@GMATPrepNow posted a reply to The price of a consumer good increased by p% in the Problem Solving forum
“Let $100 be the original price The price of a consumer good increased by p% during 2012 p% = p/100, so a p% INCREASE is the same a multiplying the original price by 1 + p/100 So, the new price = ($100)(1 + p/100) The price then decreased by 12% during 2013 A 12% DECREASE is the same a ...”
January 5, 2019
Brent@GMATPrepNow posted a reply to The number of students who attend a school could be divided in the Problem Solving forum
“The number of students who attend a school could be divided among 10, 12, or 16 buses, such that each bus transports an equal number of students. This tells us that the TOTAL number of students is a multiple of 10, 12 and 16 What is the minimum number of students that could attend the school? ...”
January 5, 2019
Brent@GMATPrepNow posted a reply to Set K consists of a finite number of consecutive odd in the Data Sufficiency forum
“Target question: What is the value of y - x? Given: Set K consists of a finite number of consecutive odd integers Statement 1: The average (arithmetic mean) of set K is –36 There''s a nice rule that says, "In a set where the numbers are equally spaced, the mean will equal the ...”
January 5, 2019
Brent@GMATPrepNow posted a reply to The value of (10^8-10^2)/(10^7-10^3) is closest to which in the Problem Solving forum
“Since the answer choices are so spread out, we can be quite aggressive with out estimation. First, 10⁸ - 10² can be rounded to 10⁸ Is this reasonable? Well, 10⁸ equals 100,000,000, so subtracting 10² (aka 100) from 100,000,000 still leaves us with approximately 100,000,000 ...”
January 5, 2019
Brent@GMATPrepNow posted a reply to Each of the 25 balls in a certain box is either red, blue, in the Data Sufficiency forum
“Target question: What is the value of P(white or even)? To solve this, we need P(A or B) = P(A) + P(B) - P(A & B) So, P(white or even) = P(white) + P(even) - P(white & even) Statement 1: P(white & even) = 0 We can add this to our probability equation to get: P(white or even) = ...”
January 4, 2019
Brent@GMATPrepNow posted a reply to The profit from the sale of a certain appliance increases, in the Data Sufficiency forum
“Target question: Did the profit exceed $4 million on sales of 380,000 units? Given: The profit from the sale of a certain appliance increases, though not proportionally, with the number of units sold. IMPORTANT: This means that we CANNOT make any "good" assumptions about the ...” January 4, 2019 Brent@GMATPrepNow posted a reply to If y = 2 + 2K and y≠0y≠0, then 1/y + 1/y + 1/y + 1/y = ? in the Problem Solving forum “Given: y = 2 + 2k Rewrite as: y/1 = (2 + 2k)/1 Flip both fractions to get: 1/y = 1/(2 + 2k) So, 1/y + 1/y + 1/y + 1/y = 1/(2 + 2k) + 1/(2 + 2k) + 1/(2 + 2k) + 1/(2 + 2k) = 4/(2 + 2k) = 4/(2)(1 + k) = 2/(1 + k) Answer: B Cheers, Brent” January 4, 2019 Brent@GMATPrepNow posted a reply to Is x/y < 0? in the Data Sufficiency forum “Target question: Is x/y < 0? Statement 1: (x^4)(y^5) < 0 There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 1 and y = -1. Notice that (x^4)(y^5) = (1^4)(-1^5) = (1)(-1) = -1, which is less than 0. In this case, x/y = 1/(-1) = -1. So, the answer to ...” January 4, 2019 Brent@GMATPrepNow posted a reply to If 4+ 1n = 55n, what is the value of n? in the Problem Solving forum “GIVEN: √(4 + 1/n) = 5√(5/n) Square both sides to get: (5)(5)√(5/n)√(5/n) Simplify right side again: 4 + 1/n = 25(5/n) Simplify right side: 4 + 1/n = 125/n Multiply both sides by n to get: 4n + 1 = 125 Subtract 1 from both sides to get: 4n = 124 Solve: n = 124/4 =31 Answer: A ...” January 3, 2019 Brent@GMATPrepNow posted a reply to On a construction site, 16 of the men wear helmets, and 19 in the Data Sufficiency forum “I thought I''d point out that Jay''s approach is also known as the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of construction worker, and the two ...” January 3, 2019 Brent@GMATPrepNow posted a reply to If the average of four numbers is 35, how many of the in the Data Sufficiency forum “Target question: How many of the numbers are less than 35? Given: The average of four numbers is 35 All this tells us is that the SUM of the 4 numbers is 140 (since 140/4 = 35) Given the limited amount of information, it''s likely that the correct answer is C or E Statement 1: None of ...” January 3, 2019 Brent@GMATPrepNow posted a reply to Absolute value in the Problem Solving forum “A quick approach is to simply test the answer choices A) -2 No good. The absolute value of something cannot be negative B) 0 Plug in to get |0² - 6| = 0. Doesn''t work. C) 1 Plug in to get |1² - 6| = 1. Doesn''t work. D) 3 Plug in to get |3² - 6| = 3. WORKS!!! Answer: D Cheers, ...” January 3, 2019 Brent@GMATPrepNow posted a reply to If m and n are positive integers such that m>n, what is t in the Data Sufficiency forum “ Given: m and n are positive integers such that m > n Target question: What is the remainder when m² – n² is divided by 21? Statement 1: The remainder when (m + n) is divided by 21 is 1 There are several values of m and n that satisfy statement 1. Here are two: Case a: m = 12 and ...” January 2, 2019 Brent@GMATPrepNow posted a reply to If x + y is not equal to 0. What is the value of (ax + ay)/( in the Data Sufficiency forum “Target question: What is the value of (ax + ay)/(x + y)? This is a good candidate for rephrasing the target question. Take the expression: (ax + ay)/(x + y) Factor the numerator to get: a(x + y)/(x + y) Simplify the fraction to get: a Since (ax + ay)/(x + y) = a, we can rephrase the target ...” January 2, 2019 Brent@GMATPrepNow posted a reply to Can n be expressed as the difference of 2 prime numbers? in the Data Sufficiency forum “Target question: Can n be expressed as the difference of 2 prime numbers? Statement 1: (n-17)(n-21) = 0 This tells us that EITHER n = 17 OR n = 21 IMPORTANT: Upon seeing that n can equal one of two values, some students will incorrectly conclude that statement 1 is not sufficient. However, ...” January 2, 2019 Brent@GMATPrepNow posted a reply to In a 200 member association consisting of men and women, exa in the Problem Solving forum “In order to minimize the number of homeowners, we must MAXIMIZE the number of men in the group, since the proportion of male homeowners (20%) is less than the proportion of female homeowners (25%) So, let''s see what happens if there are 199 men and 1 woman. If 20% (aka 1/5) of the men are ...” January 1, 2019 Brent@GMATPrepNow posted a reply to What is the value of the integer n? in the Data Sufficiency forum “Target question: What is the value of the integer n? Statement 1: n is a prime factor of 21 21 = (3)(7) So, EITHER n = 3 OR n = 7 Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT Statement 2: n is a factor of 49 49 has three positive factors: 1, ...” January 1, 2019 Brent@GMATPrepNow posted a reply to If 2x+y=3 and 4x^2-4xy+y^2=1, what is the value of xy? in the Problem Solving forum “This question becomes a lot easier if we recognize that (2x + y)² = 4x² + 4xy + y² (which is VERY similar to 4x² - 4xy + y²) Here''s what I mean: Take 2x + y = 3 and square both sides to get: (2x + y)² = 3² Simplify both sides to get: 4x² + 4xy + y²= 9 We now have two (quite ...” January 1, 2019 Brent@GMATPrepNow posted a reply to Given four rods of length 1 meter, 3 meters, 5 meters, and 7 in the Problem Solving forum “IMPORTANT RULE: If two sides of a triangle have lengths A and B, then . . . DIFFERENCE between A and B < length of third side < SUM of A and B Let''s focus on this part: length of third side < SUM of A and B We can also say that the length of LONGEST side must be less than the SUM of ...” December 31, 2018 Brent@GMATPrepNow posted a reply to Brady, Charlie, and Daryl play on the same baseball team. Th in the Data Sufficiency forum “ Given: Brady, Charlie, and Daryl play on the same baseball team. Target question: The number of home runs hit by Brady in a particular season is what fraction of the total home runs hit by the three players in that season? This is a good candidate for rephrasing the target question. Let ...” December 31, 2018 Brent@GMATPrepNow posted a reply to What is the 1st term in sequence S ? (1) The 3rd term in S in the Data Sufficiency forum “Target question: What is the 1st term in sequence S ? Statement 1: The 3rd term in S is 2 Since we''re not given any information about the NATURE of the sequence, there''s no way to answer the target question with certainty. So, statement 1 is NOT SUFFICIENT Statement 2: The 2nd term in ...” December 31, 2018 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Here''s our video on Weighted Averages video: https://www.youtube.com/watch?v=B7J6lr_qBG4 Cheers, Brent” December 31, 2018 Brent@GMATPrepNow posted a reply to Marcia's bucket can hold a maximum of how many liters of wat in the Data Sufficiency forum “Target question: Marcia''s bucket can hold a maximum of how many liters of water? In other words, what is the TOTAL CAPACITY of Marcia''s bucket? Statement 1: The bucket currently contains 9 liters of water. Not enough info to determine the TOTAL CAPACITY of Marcia''s bucket. Since we ...” December 30, 2018 Brent@GMATPrepNow posted a reply to In a stack of boards at a lumber yard, the 20th board counti in the Problem Solving forum “Let''s start from the bottom and work our way up: We''ll start with the 16th board counting from the bottom of the stack Right BELOW that 16th board, we have a board that we''ll call Larry. So, Larry is the 15th board counting from the bottom of the stack. So, starting from the bottom and ...” December 30, 2018 Brent@GMATPrepNow posted a reply to Overlapping Sets in the Data Sufficiency forum “I thought I''d point out that Manasa3190''s approach is known as the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it. Here, we have a population of people, and the two characteristics are: ...” December 30, 2018 Brent@GMATPrepNow posted a reply to Car X left Town T (RATE PROBLEM, Need Help) in the Problem Solving forum “IMPORTANT: Let''s use HOURS throughout our solution, and then convert hours to minutes at the end. When car Y had traveled for z HOURS, car Y had traveled 23 miles more that car X had from the time that car X left Town T. z = car Y''s travel time in HOURS So, z + 3/10 = car X''s travel time in ...” December 28, 2018 Brent@GMATPrepNow posted a reply to A shipping company has four empty trucks that will head out in the Problem Solving forum “Take the task of shipping the 4 boxes and break it into stages. Let''s call the 4 boxes A, B, C and D Stage 1: Select a truck to ship box A in There are 4 trucks from which to choose, so we can complete stage 1 in 4 ways Stage 2: Select a truck to ship box B in There are 4 trucks ...” December 24, 2018 Brent@GMATPrepNow posted a reply to resolution in the Data Sufficiency forum “ Given: A quorum of at least half the 20 directors must pass the resolution by at least a two-thirds majority Target question: At a meeting of the board of directors, did resolution X pass or fail? Statement 1: Ten directors voted for the resolution. KEY: We don''t know how many ...” December 23, 2018 Brent@GMATPrepNow posted a reply to a data from gmat forum in the Data Sufficiency forum “ Given: Every student at the Performing Arts Academy must take at least one of the two drama courses offered, Classical Theater or Improvisation. 15% of the students who take Classical Theater also take Improvisation Let''s use the Every student at the Performing Arts Academy must take at least ...” December 23, 2018 Brent@GMATPrepNow posted a reply to Tough Rate problem in the Data Sufficiency forum “ Given: At a certain department store present-wrapping counter, each clerk will wrap no fewer than twenty and no more than thirty presents per hour. Target question: If seventy people are standing in line, will all of their presents be wrapped after one hour? Statement 1: Each person in ...” December 23, 2018 Brent@GMATPrepNow posted a reply to Two trees have a combined height of 60 feet, and the taller in the Problem Solving forum “Let y = the height of the shorter tree The taller tree is x times the height of the shorter tree. Ho So, yx = the height of the taller tree The two trees have a combined height of 60 feet We can write: y + yx = 60 How tall is the shorter tree, in terms of x? We must solve the equation ...” December 22, 2018 Brent@GMATPrepNow posted a reply to Two water pumps, working simultaneously at their respective in the Problem Solving forum “Let''s pick some nice numbers that adhere to the given information. ...the constant rate of one pump was 1.5 times the constant rate of the other So, the fast pump has a pumping rate that''s 1.5 faster then the slow pump. So, let''s say the SLOW pump pumps at 2 gallons per hour This means ...” December 22, 2018 Brent@GMATPrepNow posted a reply to Fractions/Ratios in the Data Sufficiency forum “ Given: There are two types of rolls on a counter, plain rolls and seeded rolls. Let P = # of plain rolls Let S = # of seeded rolls Target question: What is the value of P + S? Statement 1: The ratio of the number of seeded rolls on the counter to the number of plain rolls on the ...” December 21, 2018 Brent@GMATPrepNow posted a reply to Five friends - Ross, Phoebe, Chandler, Joey and Monica - in the Problem Solving forum “Take the task of feeding the 5 friends and break it into stages. We’ll begin with the most restrictive stage(s). Stage 1: Select a pizza for Phoebe Since Phoebe will only eat Margherita pizza, there''s only 1 pizza we can serve her. So, we can complete stage 1 in 1 way Stage 2: ...” December 21, 2018 Brent@GMATPrepNow posted a reply to A list kept at Town Hall contains that town's average daily in the Data Sufficiency forum “Target question: Does this month have 30 or 31 days? IMPORTANT: Notice that the question does not ask "How many days are in this month?" If that were the case, then we''d have to consider February. Instead, the question is ruling out February by basically telling us that the month in ...” December 20, 2018 Brent@GMATPrepNow posted a reply to In how many ways can the letters D, I, G, I, T be arranged in the Problem Solving forum “One approach is to count all possible arrangements (that may or may not break the given rule) and then subtract all outcomes the break the rule. Here''s another approach. Take the task of arranging the 5 letters and break it into stages. Stage 1: Arrange the 3 CONSONANTS (D, G and T) in a ...” December 20, 2018 Brent@GMATPrepNow posted a reply to Inequalities in the GMAT Math forum “Target question: Is x² > y²? Statement 2: x > y There are several values of x and y that satisfy statement 2. Here are two: Case a: x = 2 and y = 1. In this case, x² = 4 and y² = 1. So, the answer to the target question is YES, x² IS greater than y² Case b: x = -2 and y = -3. ...” December 20, 2018 Brent@GMATPrepNow posted a reply to If sequence S has 120 terms, what is the 105th term of S? in the Data Sufficiency forum “Target question: What is the 105th term of S? Given: Sequence S has 120 terms Statement 1: The first term of S is −8. We have no information about the nature of the sequence. So, knowing the value of term 1 won''t help is determine the value of term 105 Since we cannot answer the ...” December 20, 2018 Brent@GMATPrepNow posted a reply to Two dice, each with six sides numbered 1 through 6, are toss in the Problem Solving forum “P(both dice will come up with either a 1 or a 2) = P(1st die is 1 or 2 AND 2nd die is 1 or 2) = P(1st die is 1 or 2) x P(2nd die is 1 or 2) = 2/6 x 2/6 = 1/3 x 1/3 = 1/9 Answer: C Cheers, Brent” December 20, 2018 Brent@GMATPrepNow posted a reply to At the Trenchard Oaks apartment complex, a two-bedroom apart in the Problem Solving forum “A fast and easy approach is to assign a "nice" value to the monthly rent of a ONE-bedroom apartment. Let''s say the rent on a ONE-bedroom apartment is$100 per month A two-bedroom apartment costs 50% more to rent than a one-bedroom apartment 50% of $100 =$50 So, the rent on a ...”
December 20, 2018
Brent@GMATPrepNow posted a reply to If the remainder when positive integer x is divided by 7 is in the Data Sufficiency forum
“Target question: What is the value of x? Given: If the remainder when positive integer x is divided by 7 is 4 When it comes to remainders, we have a nice rule that says: If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc. For ...”
December 20, 2018
Brent@GMATPrepNow posted a reply to The value of a share was 25% less in the 2nd quarter over in the Problem Solving forum
“Let''s assign a nice value to the share value in the 1st quarter. Let''s say the share value in the 1st quarter = $100 The value of a share was 25% less in the 2nd quarter over the 1st quarter . . . So, the share value in the 2nd quarter =$100 - (25% of $100) =$100 - $25 =$75 . . . ...”
December 20, 2018
Brent@GMATPrepNow posted a reply to The usual price of a bagel was reduced during a sale. How in the Data Sufficiency forum
“Target question: How much money could be saved by purchasing 10 bagels at the sale price rather than at the usual price? Statement 1: The usual price for a bagel is $0.50 per bagel. Since there''s no information about the SALE price, there''s no way to calculate the amount saved. Since we ...” December 20, 2018 Brent@GMATPrepNow posted a reply to One woman and one man can build a wall together in two hours in the Problem Solving forum “One approach is to determine the size of the job 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. The part in blue tells us that 2 girls have the same output as 1 man. ...” December 19, 2018 Brent@GMATPrepNow posted a reply to Is x > 0 ? (1) |x+3| < 4 (2) |x-3| < 4 in the Data Sufficiency forum “When solving inequalities involving ABSOLUTE VALUE, there are 2 things you need to know: Rule #1: If |something| < k, then –k < something < k Rule #2: If |something| > k, then EITHER something > k OR something < -k Target question: Is x > 0 ? Statement 1: |x+3| < ...” December 19, 2018 Brent@GMATPrepNow posted a reply to In the xy-plane, what is the y-intercept of line l? in the Data Sufficiency forum “Target question: What is the y-intercept of line L? IMPORTANT: When I scan the two statements, I see that they are strongly related. If the x-intercept is -1/3 (as per statement 2), the slope of the line is GUARANTEED to be 3 times its y-intercept (as per statement 1). Here''s why... ...” December 19, 2018 Brent@GMATPrepNow posted a reply to At garage sale, all of the prices of the items sold were in the Problem Solving forum “The price of the radio was the 15th highest price So, there were 14 items that were more expensive than the radio. In other words, if we listed all of the prices in ascending order, we''d get something like: ........... radio, X, X, X, X, X, X, X, X, X, X, X, X, X, X The price of the radio ...” December 19, 2018 Brent@GMATPrepNow posted a reply to A certain company charges$6 per package to ship packages in the Problem Solving forum
“Let x = the weight of the package (in pounds) So, the shipping cost = $6 + 2x We''re told the shipping cost is$38. So, we can write: 6 + 2x = 38 Subtract 6 from both sides: 2x = 32 Solve: x = 32/2 = 16 Answer: A Cheers, Brent”
December 19, 2018
Brent@GMATPrepNow posted a reply to Is x/y>1? in the Data Sufficiency forum
“Target question: Is x/y > 1? Statement 1: x > y Let''s TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 3 and y = 1. In this case, x/y = 3/1 = 3. So, the answer to the target question is YES, x/y IS greater than 1 Case b: x = ...”
December 19, 2018
Brent@GMATPrepNow posted a reply to How many 4-digit numbers greater than 3,000 have the digits: in the Problem Solving forum
“Take the task of creating 4-digit numbers and break it into stages. We’ll begin with the most restrictive stage. Stage 1: Select the first digit (to go in the thousands place) Since the 4-digit number must be GREATER THAN 3000, the first digit must be greater than or equal to 3 This means ...”
December 19, 2018
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
December 18, 2018
Brent@GMATPrepNow posted a reply to At a certain university, the ratio of the number of teaching in the Problem Solving forum
“We can solve this using equivalent ratios We''re comparing teaching assistants/number of students Let x = number of students possible We can write: 5/x = 3/80 Cross multiply to get: 3x = (5)(80) Simplify: 3x = 400 Solve: x = 400/3 = 133 1/3 = 133.3333 Since 134 students would exceed ...”
December 18, 2018
Brent@GMATPrepNow posted a reply to Automobile A is traveling at two-thirds the speed that in the Data Sufficiency forum
“ Given: Automobile A is traveling at two-thirds the speed that Automobile B is traveling. Let A = Car A''s speed Let B = Car B''s speed So, we can write: A = (2/3)B Target question: What is the value of A? Statement 1: If both automobiles increased their speed by 10 miles per hour, ...”
December 18, 2018
Brent@GMATPrepNow posted a reply to If every boy in a kindergarten class buys a soda and every g in the Problem Solving forum
“Let B = # of boys in kindergarten Let G = # of girls in kindergarten Let J = price (in CENTS) of ONE juice box Let S = price (in CENTS) of ONE soda If every boy in a kindergarten class buys a soda and every girl in the same class buys a juice box, the class will spend 1¢ less in total than it ...”
December 17, 2018
Brent@GMATPrepNow posted a reply to Sanjana jogged uphill for a while at an average speed of 3 m in the Problem Solving forum
“You could also try testing the answer choices. Cheers, Brent”
December 17, 2018
Brent@GMATPrepNow posted a reply to If 3x + 12 = 21, then x + 4 = A. 3 B. 4 C. 5 D. 7 E. 9 in the Problem Solving forum
“One option is to first solve the equation, 3x + 12 = 21, for x, and then determine the value of x+4. Alternatively, we can factor the left side to get: 3(x + 4) = 21 Now divide both sides by 3 to get: x + 4 = 7 Answer: D Cheers, Brent”
December 17, 2018
Brent@GMATPrepNow posted a reply to If a, b & c are integers, is abc odd? in the Data Sufficiency forum
“Some important rules: #1. (ODD)(ODD) = ODD #2. (ODD)(EVEN) = EVEN #3. (EVEN)(EVEN) = EVEN Given: a, b & c are integers Target question: Is abc odd? Statement 1: ab is odd This tells us that a and b are both odd. However, we have no information about c. Consider these two ...”
December 17, 2018
Brent@GMATPrepNow posted a reply to In the coordinate plane, the y-intercept of the line k is eq in the Problem Solving forum
“One approach is to choose some values that meet the given information. In the coordinate plane, the y-intercept of the line k is equal to twice its slope. Okay, so let''s say the y-intercept of line k is 6. We get: https://i.imgur.com/qJ5GeRQ.png Since the y-intercept (6) is TWICE the ...”
December 17, 2018
Brent@GMATPrepNow posted a reply to Sanjana jogged uphill for a while at an average speed of 3 m in the Problem Solving forum
“Let''s start with a "Word Equation" (distance traveled uphill) + (distance traveled downhill) = TOTAL DISTANCE Let t = the time spent jogging UPHILL (in hours) The total travel time = 40 minutes = 2/3 HOURS So, 2/3 - t = the time spent jogging DOWNHILL (in hours) Distance = ...”
December 16, 2018
Brent@GMATPrepNow posted a reply to If one manual weighs 400 grams, how many kilograms does a in the Problem Solving forum
“Since the answer choices are VERY SPREAD APART, we can be quite aggressive with our ESTIMATION. (400 grams)(50 manuals) = 20,000 grams = 20 KILOgrams So, the answer is approximately 20 Answer: C Cheers, Brent”
December 16, 2018
Brent@GMATPrepNow posted a reply to Madge paid A dollars for R bananas. Dean paid B dollars for in the Data Sufficiency forum
“ Given: Madge paid A dollars for R bananas. Dean paid B dollars for S bananas. Target question: Which one of them paid a higher price-per-banana? Statement 1: B > A This tells us that Dean PAID more than Madge paid. However, we don''t know HOW MANY bananas each person bought. ...”
December 15, 2018
Brent@GMATPrepNow posted a reply to Jason's salary and Karen's salary were each p percent in the Data Sufficiency forum
“Target question: What is the value of p? Given: Jason''s salary and Karen''s salary were each p percent greater in 1998 than in 1995. IMPORTANT: If my 1998 salary is p percent greater than my 1995 salary, then: 1998 salary = (1 + p/100)(1995 salary) For example, if my 1998 salary is 7 percent ...”
December 15, 2018
Brent@GMATPrepNow posted a reply to If w + 2x = 150, 2w + 3y = 100, and x + 3z = 50, what is the in the Problem Solving forum
“GIVEN: w + 2x = 150 2w + 3y = 100 x + 3z = 50 If we add all 3 equations, we get: 3w + 3x + 3y + 3z = 300 Divide both sides by 3 to get: w + x + y + z = 100 Answer: D Cheers, Brent”
December 15, 2018
Brent@GMATPrepNow posted a reply to If A is the center of the circle shown above and AB = BC in the Problem Solving forum
“First recognize that all radii (indicated with BLUE lines) have equal length https://i.imgur.com/iz8ur0Z.png Since BC and CD are both equal to the radius AB, we can see that all BLUE lines have equal length https://i.imgur.com/mF0UxTp.png This means the 2 blue triangles are EQUILATERAL ...”
December 13, 2018
Brent@GMATPrepNow posted a reply to If m and n are positive integers, is mn an even number? in the Data Sufficiency forum
“Some important rules: #1. ODD +/- ODD = EVEN #2. ODD +/- EVEN = ODD #3. EVEN +/- EVEN = EVEN #4. (ODD)(ODD) = ODD #5. (ODD)(EVEN) = EVEN #6. (EVEN)(EVEN) = EVEN Target question: Is mn an even number? Given: m and n are positive integers Statement 1: m/n is an even number. ...”
December 13, 2018
Brent@GMATPrepNow posted a reply to What distance did Jane travel? in the Data Sufficiency forum
“Target question: What distance did Jane travel? Statement 1: Bill traveled 40 miles in 40 minutes. No info about Jane Statement 1 is NOT SUFFICIENT Statement 2: Jane traveled at the same average rate as Bill We don''t know Bill''s speed (rate) Statement 2 is NOT SUFFICIENT ...”
December 13, 2018
Brent@GMATPrepNow posted a reply to If Mike buys a biclycle and a helmet for a total cost of in the Data Sufficiency forum
“Target question: How much does the helmet cost? Given: bicycle + helmet = $315 Statement 1: The bicycle costs twice as much as the helmet. Let x = cost of helmet So, 2x = cost of bicycle Since the total cost is$315, we can write: x + 2x = 315 Simplify: 3x = 315 Solve: x = 315/3 = ...”
December 13, 2018
Brent@GMATPrepNow posted a reply to In isosceles triangle DEF, what is the measure of angle E? in the Data Sufficiency forum
“Target question: What is the measure of ∠E? Given: Triangle DEF is an ISOSCELES triangle This tells us that there are 2 equal angles Statement 1: ∠D measures 42 degrees Here it''s hard to tell whether there''s a second 42-degree angle or whether the other two angles are different. ...”
December 12, 2018
Brent@GMATPrepNow posted a reply to Ramon wants to cut a rectangular board into identical square in the Problem Solving forum
“If we aren''t wasting any wood, the length and width must be divisible by one side of the square So, this question is a clever way of asking us what the greatest common divisor (GCD) of 18 and 30 The GCD of 18 and 30 is 6, so if we cut squares that are 6 x 6, then we won''t waste any wood. We ...”
December 12, 2018
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 ...”
December 12, 2018
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 ...”
December 12, 2018
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/”
December 12, 2018
Brent@GMATPrepNow posted a reply to How many perfect squares lie between 2^4 and 2^8, inclusive? in the Problem Solving forum
“First rewrite 2^4 and 2^8 as SQUARES of integers (aka perfect squares) 2^4 = (2²)² = 4² 2^8 = (2^4)² = 16² So, we want to find the number of perfect squares FROM 4² to 16² inclusive Let''s list them: 4², 5², 6², 7², 8², 9², 10², 11², 12², 13², 14², 15², and 16² There are ...”
December 12, 2018
Brent@GMATPrepNow posted a reply to If 5x + 3y = 17, what is the value of x? in the Data Sufficiency forum
“Target question: What is the value of x? Given: 5x + 3y = 17 Statement 1: x is a positive integer Let''s TEST some values. There are several values of x and y that satisfy statement 1. Here are two: Case a: x = 1 and y = 4 (these values satisfy the given equation, 5x + 3y = 17). In ...”
December 12, 2018
Brent@GMATPrepNow posted a reply to How many integers between 324,700 and 458,600 have tens in the Problem Solving forum
“We want to determine how many integers end in 13 For example, 324713, 324813, 324913, 325013, . . . etc. Recognize that, for every 100 consecutive integers, only 1 will end in 13. There are 133,900 integers between 324,700 and 458,600 (since 458,600 - 324,700 = 133,900) Of those 133,900 ...”
December 11, 2018
Brent@GMATPrepNow posted a reply to The quadrilateral ABCD is a square with sides of length 12. in the Problem Solving forum
“This question could take a while to answer (especially if you don''t know where to begin! :-). Fortunately, we can take advantage of an IMPORTANT feature about geometric diagrams on the GMAT: The diagrams in GMAT problem solving questions are DRAWN TO SCALE unless stated otherwise. We have ...”
December 11, 2018
Brent@GMATPrepNow posted a reply to A palindrome is a number that reads the same forward and in the Problem Solving forum
“Take the task of building palindromes and break it into stages. Stage 1: Select the ten-thousands digit We can choose 1, 2, or 3 So, we can complete stage 1 in 3 ways Stage 2: Select the thousands digit We can choose 1, 2, or 3 So, we can complete stage 2 in 3 ways Stage 3: Select ...”
December 11, 2018
Brent@GMATPrepNow posted a reply to This year, a woman has a lucrative one-year position. During in the Problem Solving forum
“Let T = the woman''s total salary for the year During this year, she will give a fraction f of her salary to her husband, a private investor, to invest and they will live this year on the remainder. So, the amount SAVED (and then given to huspand)= fT This means the amount SPENT = T - fT ...”
December 11, 2018
Brent@GMATPrepNow posted a reply to A frog is climbing a greasy pole. The frog can climb 2 in the Problem Solving forum
“Let''s solve this by making table Time elapsed | height 1 hours | 4 cm 2 hours | 8 cm REST (slide) 2.5 hours | 7 cm 3.5 hours | 11 cm 4.5 hours | 15 cm REST (slide) 5 hours | 14 cm 6 hours | 18 cm 7 hours | 22 cm REST (slide) 7.5 hours | 21 cm 8.5 hours | 25 cm 9.5 hours | 29 cm ...”
December 11, 2018
Brent@GMATPrepNow posted a reply to Oil, vinegar, and water are mixed in a 3 to 2 to 1 ratio to in the Problem Solving forum
“GIVEN: oil: vinegar : water = 3 : 2 : 1 Let''s first try to use ALL 8 cups of oil Take 3 : 2 : 1 and multiply all 3 parts by 8/3 to get the EQUIVALENT ratio 8 : 16/3 : 8/3 Simplify to get: 8 : 5 1/3 : 2 2/3 So, in this case, the dressing is comprised of 8 cups of oil, 5 1/3 cups of vinegar, ...”
December 10, 2018
Brent@GMATPrepNow posted a reply to Line DB divides Rectangle ABCD into two equal triangles. Is in the Data Sufficiency forum
“IF all 4 sides of the rectangle have EQUAL length (i.e,, the shape is a square), then the diagonal will create two 45-45-90 right triangles. However, if the sides are not all the same length, the resulting triangles will NOT be 45-45-90 right triangles. Cheers, Brent”
December 10, 2018
Brent@GMATPrepNow posted a reply to A father distributed his total wealth to his two sons. How in the Data Sufficiency forum
“ Given: A father distributed his total wealth to his two sons. Target question: How much wealth did the father have? Statement 1: The elder son received 3/5 of the wealth. Without any dollar values, there''s no way to answer the target question with certainty. So, statement 1 is NOT ...”
December 10, 2018
Brent@GMATPrepNow posted a reply to At what speed was Erik running when he was at the halfway po in the Data Sufficiency forum
“IMPORTANT: The two statements essentially provide the exact same information. If it took Erik 2 hours to travel 10 miles, we can conclude that his average speed was 5 miles per hour. When the two statements provide the same information in a Data Sufficiency question, the correct answer must be ...”
December 10, 2018
Brent@GMATPrepNow posted a reply to [x] is the greatest integer less than or equal to x. What is in the Data Sufficiency forum
“Here are a few similar questions to practice with: - https://www.beatthegmat.com/if-is-the-greatest-integer-less-than-or-equal-to-x-what-t302459.html - https://www.beatthegmat.com/g-x-is-the-greatest-integer-less-than-or-equal-to-x-t298237.html - ...”
December 10, 2018
Brent@GMATPrepNow posted a reply to When 6 is multiplied by x, the result is the same as when x in the Problem Solving forum
“When 6 is multiplied by x, the result is the same as when x is added to 9 In other words: 6x = 9 + x Subtract x from both sides: 5x = 9 Divide both sides by 5 to get: x = 9/5 Answer: E Cheers, Brent”
December 9, 2018
Brent@GMATPrepNow posted a reply to Three photographers, Lisa, Mike and Norm, take photos of a w in the Problem Solving forum
“We can also solve the question using 1 variable Norms photos number 10 more than twice the number of Lisa''s photos Let x = the number of photographs that Lisa took. So, 2x + 10 = the number of photographs that Norm took. The total of Lisa and Mikes photos is 50 less than the sum of ...”
December 9, 2018
Brent@GMATPrepNow posted a reply to At a certain factory, each employee working the second shift in the Problem Solving forum
“Let''s assign a "nice" value to the number of widgets made by ONE employee. We''ll also assign a nice value to the number of employees on each shift. At a certain factory, each employee working the SECOND shift produced 2/3 as many widgets as each employee working the FIRST shift. ...”
December 9, 2018
Brent@GMATPrepNow posted a reply to If two of the four expressions x+y, x+5y, x-y, and 5x-y are in the Problem Solving forum
“Okay, first recognize that x² - (by)² is a DIFFERENCE OF SQUARES. Here are some examples of differences of squares: x² - 25y² 4x² - 9y² 49m² - 100k² In general, we can factor differences of squares as follows: a² - b² = (a-b)(a+b) So . . . x² - 25y² = (x+5y)(x-5y) 4x² - ...”
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
Brent@GMATPrepNow posted a new topic called CHALLENGE: What is the value of k? in the Data Sufficiency forum
“What is the value of k? $$(1) k^2-5k-66=0$$ $$(2) \frac{2k}{k^2+5k}=\frac{1}{8}$$ Source: www.gmatprepnow.com Answer: B Estimated difficulty level: 600-650”
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 Brent@GMATPrepNow posted a reply to Circle question help in the Problem Solving forum “We''ll begin by arbitrarily placing point A somewhere on the circumference. https://i.imgur.com/hRHtq4o.png So, we want to know the probability that a randomly-placed point B will yield a chord AB that is at least 2 cm long. So, let''s first find a location for point B that creates a chord ...” December 7, 2018 Brent@GMATPrepNow posted a reply to Let C be defined as the sum of all prime numbers between in the Problem Solving forum “C = 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 = 129 So, C/3 = 129/3 = 43 Answer: E Cheers, Brent” December 7, 2018 Brent@GMATPrepNow posted a reply to 2k years ago Frank was 3k years old. In k years Frank's age, in the Problem Solving forum “These kinds of questions (Variables in the Answer Choices - VIACs) can be answered algebraically or using the input-output approach. Mitch has solved the question using the input-output approach, so let''s use the algebraic approach. 2k years ago Frank was 3k years old. We''re given Frank''s ...” December 7, 2018 Brent@GMATPrepNow posted a reply to In a 200 member association consisting of men and women, exa in the Problem Solving forum “In order to minimize the number of homeowners, we must MAXIMIZE the number of men in the group, since the proportion of male homeowners (20%) is less than the proportion of female homeowners (25%) So, let''s see what happens if there are 199 men and 1 woman. If 20% (aka 1/5) of the men are ...” December 6, 2018 Brent@GMATPrepNow posted a reply to If all of the telephone extensions in a certain company must in the Problem Solving forum “NOTE: Always SCAN the answer choices before performing any calculations. Here, we notice that the answer choices are pretty small, so if we don''t come up a full solution, we should consider LISTING AND COUNTING We get the following extensions: 1236 1326 1362 1632 2136 2316 3126 3162 ...” December 6, 2018 Brent@GMATPrepNow posted a reply to If all of the telephone extensions in a certain company must in the Problem Solving forum “Take the task of arranging the 4 digits and break it into stages. We’ll begin with the most restrictive stage. Stage 1: Select the digit in the units position Since the 4-digit extension must be EVEN, the unit digit must be either 2 or 6 So, we can complete stage 1 in 2 ways Stage ...” December 6, 2018 Brent@GMATPrepNow posted a reply to What was the revenue that a theater received from the sale in the Data Sufficiency forum “Target question: What was the revenue that a theater received from the sale of 400 tickets Jump straight to . . . Statements 1 and 2 combined The combined statements tell us that 100 tickets sold for the full price of$25 each. The remaining 300 tickets were sold at some reduced price. ...”
December 6, 2018
Brent@GMATPrepNow posted a reply to A certain high school offers two foreign languages, Spanish in the Problem Solving forum
“Another approach is to use the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it (aka overlapping sets questions). Here, we have a population of students, and the two characteristics are: - ...”
December 6, 2018
Brent@GMATPrepNow posted a reply to In year x, it rained on 40% of all Mondays and 20% of all in the Data Sufficiency forum
“In any given year, there will be 52 or 53 Mondays, 52 or 53 Tuesdays, etc. So, it''s impossible to say that it rained on 40% of all Mondays or 20% of all Tuesdays, etc. For example, if there are 52 Mondays, then 40% of 52 = 20.8, which means that it rained on 20.8 days (impossible). Cheers, ...”
December 6, 2018
Brent@GMATPrepNow posted a reply to Three men sit at a table. One dollar is placed in front of in the Problem Solving forum
“Let''s see what happens if a man waits until the last (5th) round to take the money. Round #1: $1 placed in front of the man (but he doesn''t take it) Round #2: Now,$2 placed in front of the man (but he doesn''t take it) Round #3: Now, $4 placed in front of the man (but he doesn''t take it) ...” December 5, 2018 Brent@GMATPrepNow posted a reply to If a, b, and c are positive integers such that a < b < in the Data Sufficiency forum “Target question: Is a% of b% of c an integer? This is a great candidate for rephrasing the target question. Aside: We have a free video with tips on rephrasing the target question: a% of b% of c is the same as (a/100)(b/100)(c), which equals abc/10,000 So, we can rephrase the target ...” December 5, 2018 Brent@GMATPrepNow posted a reply to If w, x, and y are consecutive odd positive integers and w & in the Problem Solving forum “Here''s a 3rd approach: GIVEN: w, x, and y are consecutive odd positive integers and w < x < y Since consecutive odd integers go up by 2, we can write: x = w + 2, and y = w + 2 + 2 = w + 4 So, y - x - w = (w + 4) - (w + 2) - w = w + 4 - w - 2 - w = 2 - w Since w is an ODD integer, ...” December 5, 2018 Brent@GMATPrepNow posted a reply to What is the difference between the number of three-member in the Problem Solving forum “The number of three-member committees that can be formed from a group of nine members Since the order in which we select the 3 people does not matter, we can use combinations. We can choose 3 people from 9 people in 9C3 ways 9C3 = (9)(8)(7)/(3)(2)(1) = 84 three-member committees The total ...” December 5, 2018 Brent@GMATPrepNow posted a reply to All the 7 books of the fictional character series Horry in the Problem Solving forum “At$8 per book, the 8 books SHOULD have cost $64 (8 x$8 = $64) However, Harry bought the 8 books for$60 So, the amount Harry saved = $64 -$60 = $4 What is savings percentage for Harry, who bought the whole set together? Percent savings = 100(amount saved)/(original price) = 100(4)/64 = ...” December 5, 2018 Brent@GMATPrepNow posted a reply to Charlie takes 2.5 hours to fly from Los Angeles to Mexico Ci in the Problem Solving forum “Average speed = (total distance traveled)/(total travel time) So, Average speed = 1200/2.5 = 2400/5 = 4800/10 = 480 mph Answer: D Cheers, Brent” December 4, 2018 Brent@GMATPrepNow posted a reply to In her position as a real estate agent, Sarah receives a bon in the Problem Solving forum “Last week, Sarah earned a$4,000 bonus, which decreased her average bonus amount to $4800. This represents a decrease of 4%. Let x = OLD average bonus amount We can write: x - 0.04x =$4800 Simplify: 0.96x = $4800 Solve: x =$4800/(0.96) = $5000 How many sales has Sarah made? Let n = the ...” December 4, 2018 Brent@GMATPrepNow posted a reply to If there are 4 pairs of twins, and a committee will be in the Problem Solving forum “Here''s another approach. Take the task of selecting the 3 committee members and break it into stages. Stage 1: Select the 3 twins from which we will select 1 spouse each. There are 4 sets of twins, and we must select 3 of them. Since the order in which we select the 3 twins does not ...” 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
Brent@GMATPrepNow posted a reply to For each of her sales, a saleswoman receives a commission in the Problem Solving forum
“Saleswoman receives a commission equal to 20 percent of the first $500 of the total amount of the sale, plus 30 percent of the total amount in excess of$500 If she sold $800, then... Commission = (20 percent of$500) + (30 percent of $300) =$100 + $90 =$190 The saleswoman''s commission ...”
December 1, 2018
Brent@GMATPrepNow posted a reply to Portia purchased a laptop for $480, but after checking the in the Problem Solving forum “Let x = the INTENDED price of the laptop Portia was overcharged by 20% So, x + (20% of x) = the amount Portia paid In other words: x + 0.2x =$480 Simplify: 1.2x = 480 Solve: x = 480/1.2 = 400 So, Portia was SUPPOSED to pay $400, but she actually paid$480 So, Portia was overcharged ...”
December 1, 2018
Brent@GMATPrepNow posted a reply to When a certain tree was first planted, it was 4 feet tall in the Problem Solving forum
“Height of tree on day 0 = 4 Let d = the height increase each year Height of tree at the end of the 1st year = 4+d Height of tree at the end of the 2nd year = 4+d+d = 4 + 2d Height of tree at the end of the 3rd year = 4+d+d+d = 4 + 3d Height of tree at the end of the 4th year = 4+d+d+d+d = 4 + ...”
December 1, 2018
Brent@GMATPrepNow posted a reply to Last Friday a certain shop sold 3/4 of the sweaters in its in the Data Sufficiency forum
“ Given: Last Friday a certain shop sold 3/4 of the sweaters in its inventory. Each sweater sold for $20. Target question: What was the total revenue last Friday from the sale of this sweaters? Statement 1: When the shop opened last Friday, there were 160 sweaters in its inventory. 3/4 ...” November 30, 2018 Brent@GMATPrepNow posted a reply to When running a mile during a recent track meet, Nuria was in the Problem Solving forum “The long approach is to meticulously convert 11/25 of a minute to seconds, and then ADD that unaccounted time to Nuria''s recorded time (of 5 minutes, 44 seconds) However, when we check the answer choices before performing any calculations (ALWAYS check the answer choices before performing any ...” November 30, 2018 Brent@GMATPrepNow posted a reply to GMAT PREP CR... why is A wrong? in the Critical Reasoning forum “A student asked me to answer this question, so here it goes . . . 1) Read the question stem to determine the question type. Tricky! With fill-in-the-blank questions, it''s often difficult to determine the question type. The last sentence reads Unitron is not going to hire department heads ...” November 29, 2018 Brent@GMATPrepNow posted a reply to New cars leave a car factory in a repeating pattern of red, in the Problem Solving forum “Let''s examine the pattern. CAR # | color 1 | red 2 | blue 3 | black 4 | gray 5 | red 6 | blue 7 | black 8 | gray 9 | red . . . The pattern REPEATS EVERY 4 CARS. So, we say the pattern has CYCLE 4 Also, notice that every car # that''s divisible by 4 is gray So, let''s find a ...” November 29, 2018 Brent@GMATPrepNow posted a reply to If each of the two digits X and Y is distinct, is the two di in the Data Sufficiency forum “Target question: Is the two-digit integer xy prime? Given: Each of the two digits x and y is distinct Statement 1: Each of the digits x and y is the sum of 2 distinct single digit prime numbers. Let''s TEST some values. There are several values of x and y that satisfy statement 1. Here ...” November 29, 2018 Brent@GMATPrepNow posted a reply to Joan spent$10 to buy at least one piece each of apples and in the Data Sufficiency forum
“Target question: How many apples did Joan buy? Given: Joan spent $10 to buy at least one piece each of apples and oranges at a store where each apple cost$2 and each orange cost $1. Since there are only a handful of possible outcomes, we might benefit from quickly listing them: i) Joan ...” November 29, 2018 Brent@GMATPrepNow posted a reply to If 320 people attended the wedding and 200 attendees drank in the Data Sufficiency forum “This question is somewhat ambiguous, since it''s hard to say whether "nondrinkers" in statement 1 refers to people who drank neither beer nor wine, or did not drink beer. I''m assuming that it means to not drink beer, so I''ve add that to the question below. One approach is to use ...” November 28, 2018 Brent@GMATPrepNow posted a reply to Difficult Manhatan Problem in the Problem Solving forum “Target question: What is the hundreds digit of the product AB? Given: The difference between positive two-digit integer A and the smaller two-digit integer B is twice A‘s units digit Let x = the tens digit of A, and let y = the units digit of A So, the VALUE of A = 10x + y From the ...” November 28, 2018 Brent@GMATPrepNow posted a reply to If a child is randomly selected from Columbus Elementary in the Data Sufficiency forum “Target question: What is the probability that the child will be a boy? This is a good candidate for rephrasing the target question. Let G = # of girls in the school Let B = # of boys in the school So, G + B = total number of children in the school So, P(selected child is a boy) = B/(G + B) ...” November 28, 2018 Brent@GMATPrepNow posted a reply to A club has 10 members. One president and two vice-presidents in the Problem Solving forum “Take the task of selecting the president and two vice-presidents and break it into stages. Stage 1: Select the president There are 10 people to choose from. So, we can complete stage 1 in 10 ways Stage 2: Select two people to be the vice-presidents Since the order in which we select the ...” November 28, 2018 Brent@GMATPrepNow posted a reply to On a partly cloudy day, Derek decides to walk back from work in the Problem Solving forum “Let''s PLUG IN a nice value for the total distance traveled. If Derek''s average speed is 2.8 mph, then let''s say that he traveled a total of 28 miles. At an average rate of 2.8 mph, a 28 mile trip will take 10 hours. Since Derek''s average speed is BETWEEN 2 and 3 mph, we can conclude that ...” November 28, 2018 Brent@GMATPrepNow posted a reply to The weights of four packages are 1, 3, 5, and 7 pounds, resp in the Problem Solving forum “That''s MUCH better than my solution!! Cheers, Brent<i class="em em---1"></i>” November 27, 2018 Brent@GMATPrepNow posted a reply to The weights of four packages are 1, 3, 5, and 7 pounds, resp in the Problem Solving forum “For each answer choice, if we CAN create the total given weight, then we can ELIMINATE that answer choice. a) 9 = 1 + 3 + 5 ELIMINATE b) 10 = 3 + 7 ELIMINATE c) 12 = 5 + 7 ELIMINATE d) 13 = 1 + 5 + 7 ELIMINATE By the process of elimination, the correct answer is E Cheers, Brent” November 27, 2018 Brent@GMATPrepNow posted a reply to If 1+2+2^2+... +2^n=2^{n+1}-1, what is the largest prime fac in the Problem Solving forum “GIVEN: 1 + 2 + 2^2 + ... + 2^n = 2^{n+1} - 1 So, 1 + 2 + 2^2 + ... + 2^7 = 2^{7+1} - 1 = 2^8 - 1 If we recognize that the above expression is a difference of squares, we can factor it to get.... 2^8 - 1 = (2^4 + 1)(2^4 - 1) = (2^4 + 1)(2^2 + 1)(2^2 - 1) = (16 + 1)(4 + 1)(4 - 1) = ...” November 27, 2018 Brent@GMATPrepNow posted a reply to How many integers from 0 to 50, inclusive, have a remainder in the Problem Solving forum “When it comes to remainders, we have a nice rule that says: If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc. For example, if k divided by 5 leaves a remainder of 1, then the possible values of k are: 1, 1+5, 1+(2)(5), 1+(3)(5), ...” November 27, 2018 Brent@GMATPrepNow posted a reply to Is b even? in the Data Sufficiency forum “Target question: Is b even? KEY POINT: We are not told that a and b are INTEGERS. As such, we can jump straight to. . . . Statements 1 and 2 combined There are several values of a and b that satisfy BOTH statements. Here are two: Case a: a = 4 and b = 2. Notice that a/b = 4/2 = 2, ...” November 27, 2018 Brent@GMATPrepNow posted a reply to In the rectangular coordinate system shown above, does the in the Data Sufficiency forum “Target question: Does line k intersect quadrant II? Statement 1: The slope of k is -1/6 Here are a few lines with slope -1/6 https://i.imgur.com/1p6USLh.png KEY CONCEPT: As we travel from right to left along a line with slope -1/6, we keep moving up. So, at some point, the line will ...” November 27, 2018 Brent@GMATPrepNow posted a reply to A certain recipe calls for 2 cups of sugar and 3 1/2 cups of in the Problem Solving forum “Judging from the OA, I''ve added some key text below A certain recipe calls for 2 cups of sugar and 3 1/2 cups of flour So sugar/flour = 2/3.5 Check answer choices . . . . not there. Looks like we need to create a ratio that''s EQUIVALENT to 2/3.5 Multiply top and bottom by 2 to get ...” November 27, 2018 Brent@GMATPrepNow posted a reply to When the positive integer x is divided by 6, the remainder in the Problem Solving forum “Good catch - thanks Fabio! I''ve edited my response accordingly. Cheers, Brent” November 26, 2018 Brent@GMATPrepNow posted a reply to In a certain state, gasoline stations compute the price per in the Problem Solving forum “In a certain state, gasoline stations compute the price per gallon "p", in dollars, charged at the pump by adding a 4 percent sales tax to the dealer''s price per gallon "d", in dollars . . . We can write: p = d + 4% of d = d + 0.04d = 1.04d So, we have: p = 1.04d . . . ...” November 26, 2018 Brent@GMATPrepNow posted a reply to When the positive integer x is divided by 6, the remainder in the Problem Solving forum “APPROACH#2 When the positive integer x is divided by 6, the remainder is 4 In other words, x is 4 greater than some multiple of 6 We can write: x = 6k + 4, where k is an integer If x = 6k + 4, we can also write: x = 6k + 3 + 1 Factor to get: x = 3(2k + 1) + 1 Since 2k+1 must be an integer, ...” November 26, 2018 Brent@GMATPrepNow posted a reply to When the positive integer x is divided by 6, the remainder in the Problem Solving forum “----ASIDE------------------- When it comes to remainders, we have a nice rule that says: If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc. For example, if k divided by 5 leaves a remainder of 1, then the possible values of k are: 1, ...” November 26, 2018 Brent@GMATPrepNow posted a reply to A chili recipe calls for the final mixture to consist of 1/2 in the Problem Solving forum “A chili recipe calls for the final mixture to consist of 1/2 meat and 1/3 beans, with the remainder an even mixture of sauce and various spices Let''s see what fraction of the final mixture is sauce and various spices 1/2 + 1/3 = 3/6 + 2/6 = 5/6 If 5/6 of the mixture is meat and beans, then the ...” November 26, 2018 Brent@GMATPrepNow posted a reply to A store sells only two types of shirts, branded and in the Data Sufficiency forum “ Given: All the branded shirts are priced at$60 per unit and all the non-branded shirts are priced at $20 per unit. On a certain day, the store sold a total of 30 shirts. Let B = # of branded shirts sold Let N = # of non-branded shirts sold If a TOTAL of 30 shirts were sold, we can write: N + ...” November 26, 2018 Brent@GMATPrepNow posted a reply to Of the 4,800 voters who voted for or against Resolution K, in the Data Sufficiency forum “Target question: What was the total number of female voters who voted for Resolution K? When solving Data Sufficiency questions, it''s important that you don''t perform more calculations than are necessary. So, for this question, we need only determine whether or not we have sufficient ...” November 26, 2018 Brent@GMATPrepNow posted a reply to If x and y are nonnegative integers, what is the value of y? in the Data Sufficiency forum “The above solutions are great. I just wanted to add that whenever you''re told that a value is non-negative on the GMAT, you should be sure to consider what happens when that value equals zero Keep in mind that, if the test-makers wanted to restrict a value to POSITIVE values only, then they''d ...” November 25, 2018 Brent@GMATPrepNow posted a reply to If n is the smallest integer such that 432 times n is the in the Problem Solving forum “IMPORTANT CONCEPT: The prime factorization of a perfect square (the square of an integer) will have an even number of each prime For example: 400 is a perfect square. 400 = 2x2x2x2x5x5. Here, we have four 2''s and two 5''s This should make sense, because the even numbers allow us to split the ...” November 25, 2018 Brent@GMATPrepNow posted a reply to Set P {a, b, c, d, e, f, g} Set Q {a, b, c, d, e, f} If a, b in the Problem Solving forum “The key here is MUST be true. So, if we can find an example in which a statement is NOT true, then we can ELIMINATE it. We have: Set P {a, b, c, d, e, f, g} Set Q {a, b, c, d, e, f} I''ll make the extra value red so it''s easier to compare the two sets So, the sets COULD be: Set P {1, 2, ...” November 25, 2018 Brent@GMATPrepNow posted a reply to Every object in a box is either a sphere or a cube, and ever in the Data Sufficiency forum “Target question: How many objects are in the box? Given: Every object in a box is either a sphere or a cube, and every object in the box is either red or green. We can solve this using the Double Matrix Method. This technique can be used for most questions featuring a population in which ...” November 25, 2018 Brent@GMATPrepNow posted a reply to Last month, a florist gave 7 percent of her sales revenue to in the Problem Solving forum “Choose a "nice" number for the sales revenue Let$100 = LAST MONTH''s revenue So, $120 = THIS MONTH''s revenue (since sales were up 20 percent from last month) LAST month, a florist gave 7 percent of her sales revenue to her employees in bonuses So, bonuses = 7% of$100 = $7 ...” November 23, 2018 Brent@GMATPrepNow posted a reply to In a plane, there are two parallel lines. One line has 5 in the Problem Solving forum “There are two ways in which we can create a triangle. #1) Select 2 points from the 5-point line and select 1 point from the 4-point line. #2) Select 2 points from the 4-point line and select 1 point from the 5-point line. #1) Select 2 points from the 5-point line and select 1 point from the ...” November 23, 2018 Brent@GMATPrepNow posted a reply to GMAT PREP KAPLAN VIDEO in the The 60-Day GMAT Study Guide forum “Thanks for the heads up. This video should serve as a replacement: https://www.gmatprepnow.com/module/general-gmat-strategies/video/1250 Cheers, Brent” November 23, 2018 Brent@GMATPrepNow posted a reply to Alan and Peter are cycling at different constant rates on a in the Data Sufficiency forum “ Given: Alan is NOW 3 miles ahead of Peter Target question: How many minutes from now will Peter be 1 mile ahead of Alan? Statement 1: ONE HOUR AGO, Alan was 7 miles ahead of Peter. Alan is NOW 3 miles ahead of Peter So, in one hour, the GAP between Alan and Peter decreased by 4 miles ...” November 23, 2018 Brent@GMATPrepNow posted a reply to List M consists of 50 decimals, each of which has a value be in the Problem Solving forum “Let''s examine the EXTREME CASES S - T = x percent of T So, S - T = (x/100)T Divide both sides by to get: (S - T)/T = x/100 Multiply both sides by 100 to get: x = 100(S - T)/T First, we we''ll MINIMIZE the value of x by minimizing the value of S - T and maximizing the value of T. This ...” November 23, 2018 Brent@GMATPrepNow posted a reply to R and S can complete a certain job in 6 and 4 days respectiv in the Problem Solving forum “Let''s assign a "nice" value to the job, a value that works well with the given values (6 days and 4 days ). So, let''s say the ENTIRE job is to make 24 widgets R can complete a certain job in 6 days In other words, R can make 24 widgets in 6 days So, R can make 4 widgets per day ...” November 23, 2018 Brent@GMATPrepNow posted a reply to A certain telephone company offers two plans, A and B. Under in the Problem Solving forum “Let x = the duration of the phone call (in minutes) Under plan A, the company charges a total of$0.60 for the first 7 minutes of each call and $0.06 per minute thereafter. So, the TOTAL cost =$0.60 + (x - 7 minutes)($0.06) = 0.60 + (0.06x - 0.42) = 0.06x + 0.18 Under plan B, the company ...” November 23, 2018 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “The Something Method for solving certain equations Video: https://www.youtube.com/watch?v=mmTisgtNfTI Cheers, Brent” November 21, 2018 Brent@GMATPrepNow posted a reply to If m represents the slope of a line in the coordinate geomet in the Data Sufficiency forum “Target question: Does the line intersect quadrant III? Jump straight to... Statements 1 and 2 combined Here are two scenarios that satisfy BOTH statements: Case a: m = 3 https://i.imgur.com/2SVui9E.png In this case, the answer to the target question is YES, the line DOES intersect ...” November 21, 2018 Brent@GMATPrepNow posted a reply to In the first year of a pyramid scheme, John convinced y of in the Data Sufficiency forum “Target question: What was the value of y? Statement 1: The revenue for the website that year was$36,000. First round of "investors": y people paying $30 each = 30y dollars Second round of "investors": y² people paying$15 each = 15y² dollars Total revenue = 15y² + ...”
November 21, 2018
Brent@GMATPrepNow posted a reply to Missing day 20 in the The 60-Day GMAT Study Guide forum
“Done! Cheers, Brent”
November 21, 2018
Brent@GMATPrepNow posted a reply to Luxo paint contains only alcohol and pigment. What is the in the Data Sufficiency forum
“Target question: What is the ratio of alcohol to pigment in Luxo paint? Given: Luxo paint contains ONLY alcohol and pigment. Statement 1: Exactly 7 ounces of pigment are contained in a 12-ounce can of Luxo paint. If 7 of the 12 ounces of paint are PIGMENT, then the remaining 5 ounces ...”
November 21, 2018
Brent@GMATPrepNow posted a reply to A children's theater sels tickets to a show. Tickets for in the Data Sufficiency forum
“ Given: Tickets for children cost $10 and tickets for adults cost$35. Ticket revenues from the last performance were $390 Let A = # of adults in attendance Let C = # of children in attendance So, we can write: 35A + 10C = 390 Since A and C must be POSITIVE INTEGERS, there are not many ...” November 20, 2018 Brent@GMATPrepNow posted a reply to A number when divided by 4 and 5 leaves remainders 1 and 4 in the Problem Solving forum “When it comes to remainders, we have a nice rule that says: If N divided by D, leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc. For example, if k divided by 5 leaves a remainder of 1, then the possible values of k are: 1, 1+5, 1+(2)(5), 1+(3)(5), ...” November 20, 2018 Brent@GMATPrepNow posted a reply to The number line above represents which of the following in the Problem Solving forum “We can also solve the question by testing the answer choices Here''s what I mean: The diagram tells us that x= 0 is a solution to the inequality. When we check the answer choices, we see that answer choice D (1 < 2x < 3) does NOT have x = 0 as a solution. When we let x = 0, the ...” November 19, 2018 Brent@GMATPrepNow posted a reply to If n is an integer between 30 and 50 inclusive, what is the in the Data Sufficiency forum “Target question: What is the value of n? Given: n is an integer between 30 and 50 inclusive Statement 1: When n is divided by 8, the remainder is 7 ------ASIDE-------------------------------------- When it comes to remainders, we have a nice rule that says: If N divided by D leaves ...” November 19, 2018 Brent@GMATPrepNow posted a reply to When sold at a 40% discount, a sweater nets the merchant a in the Problem Solving forum “Let''s work BACKWARDS. Let''s say the WHOLESALE price was$100 the merchant made a net profit of 20% on the wholesale cost (which was $100) So, the merchant sold the sweater for$120 Let M = the markup price on the label (before any discounts). So, 40% less than M = $120 In other ...” November 19, 2018 Brent@GMATPrepNow posted a reply to Kevin buys beer in bottles and cans. He pays$1.00 for each in the Data Sufficiency forum
“Target question: How many bottles of beer did Kevin buy? Given: Kevin pays $1.00 for each can of beer and$1.50 for each bottle of beer. Kevin buys a total of 15 bottles and cans of beer Let C = the NUMBER of Cans that Kevin bought Let B = the NUMBER of Bottles that Kevin bought So, we can ...”
November 16, 2018
Brent@GMATPrepNow posted a reply to What is the least possible product of 4 different integers, in the Problem Solving forum
“We want values with the greatest MAGNITUDE So (10)(9)(8)(-5) = -3600 Answer: -3600 Answer: B”
November 16, 2018
Brent@GMATPrepNow posted a reply to A reatil appliance store priced a video recorder at 20 in the Problem Solving forum
“A retail appliance store priced a video recorder at 20 percent above the wholesale cost of $200 20% of$200 = $40 So, the retail price =$200 + $40 =$240 If a store employee applied the 10 percent employee discount to the retail price to buy the recorder, how much did the employee pay for the ...”
November 16, 2018
Brent@GMATPrepNow posted a reply to Planning is in progress for a fenced, rectangular playground in the Problem Solving forum
“It''s a good idea to first try to understand what the graph is telling us. For example, the leftmost point on the curve has the coordinates (10, 340) This tells us that, if the length of the playground is 10 meters, then a total of 340 meters of fencing is required. This makes sense, since we ...”
November 16, 2018
Brent@GMATPrepNow posted a reply to When a certain tree was first planted, it was 4 feet tall, in the Problem Solving forum
“Height of tree on day 0 = 4 Let d = the height increase each year Height of tree at the end of the 1st year = 4+d Height of tree at the end of the 2nd year = 4+d+d = 4 + 2d Height of tree at the end of the 3rd year = 4+d+d+d = 4 + 3d Height of tree at the end of the 4th year = 4+d+d+d+d = 4 + ...”
November 16, 2018
Brent@GMATPrepNow posted a reply to In the rhombus ABCD, the length of diagonal BD is 6 and the in the Problem Solving forum
“In a rhombus, the diagonals are perpendicular bisectors. http://i1168.photobucket.com/albums/r500/GMATPrepNow/rhmbs1_zps1nyufj6q.png So, we can add our lengths as follows. http://i1168.photobucket.com/albums/r500/GMATPrepNow/rhmbs2_zpskyv3wwkl.png From here, if we focus on one of the 4 ...”
November 16, 2018
Brent@GMATPrepNow posted a reply to If xy is not equal to zero, what is the ratio of x to y? in the Data Sufficiency forum
“NOTE: We can write the ratio x:y as a fraction x/y Target question: What is the value of x/y ? Statement 1: 3x = 4y Divide both sides by y to get: 3x/y = 4 Divide both sides by 3 to get: x/y = 4/3 So, the answer to the target question is x/y = 4/3 Since we can answer the target question ...”
November 16, 2018
Brent@GMATPrepNow posted a reply to At the Trenchard Oaks apartment complex, a two-bedroom in the Problem Solving forum
“A fast and easy approach is to assign a "nice" value to the monthly rent of a ONE-bedroom apartment. Let''s say the rent on a ONE-bedroom apartment is $100 per month A two-bedroom apartment costs 50% more to rent than a one-bedroom apartment 50% of$100 = $50 So, the rent on a ...” November 15, 2018 Brent@GMATPrepNow posted a reply to If line k in the xy-coordinate plane has the equation Ax + B in the Data Sufficiency forum “ Given: Line k has the equation Ax + By = C Target question: What is the slope of line k ? This is a good candidate for rephrasing the target question. Let''s take the given equation Ax + By = C and rewrite it in slope y-intercept form, y = mx + b, where m = slope and b = y-intercept ...” November 15, 2018 Brent@GMATPrepNow posted a reply to What is the ratio of x:y:z? in the Data Sufficiency forum “Target question: What is the ratio of x:y:z? Statement 1: xy = 14 In information about z Statement 1 is NOT SUFFICIENT Statement 2: yz = 21 In information about x Statement 2 is NOT SUFFICIENT Statements 1 and 2 combined There are several values of x, y and z that satisfy BOTH ...” November 15, 2018 Brent@GMATPrepNow posted a reply to If xy : yz : zx = 1:2:3, then what is x : y : z ? in the Problem Solving forum “Let''s focus on pairs of values If xy : yz : zx = 1:2:3, then we know that xy : yz = 1:2 Take xy : yz and divide both sides by y to get the EQUIVALENT ratio x:z This means x:z = 1:2 Check the answer choices... A. 2 : 3 : 6 this answer choice says x:z = 2:6. We need x:z = 1:2 ELIMINATE A ...” November 15, 2018 Brent@GMATPrepNow posted a reply to Over a four-game stretch, Dennis's bowling scope average 240 in the Problem Solving forum “In other words, an increase from 240 to 300 represents what kind of percent increase? Percent increase = (100)(new - old)/old = (100)(300 - 240)/240 = (100)(60)/240 = (100)(1/4) = 25% Answer: B Cheers, Brent” November 15, 2018 Brent@GMATPrepNow posted a reply to The table above shows the distribution of tests scores for a in the Problem Solving forum “Since we have an ODD number of values, the median will be the MIDDLEMOST value. In other words, if we arrange all 73 values in ASCENDING order, the median will be the 37th value (i.e., 36 values are below and 36 values are above). The table says the first 2 scores in the 50-59 range. So, the 1st ...” November 15, 2018 Brent@GMATPrepNow posted a reply to # X-Axis Intercepts in the Problem Solving forum “Let''s find some points that lie on each of the curves. So, for each equation, we''ll find a pair of values (an x-value and a y-value) that satisfy each equation. We''ll do so by plugging in some x-values and calculating the corresponding y-values. Let''s start with x = 0 Plug x = 0 into ...” November 14, 2018 Brent@GMATPrepNow posted a reply to How many positive two-digit numbers yield a remainder of 1 in the Problem Solving forum “When it comes to remainders, we have a nice rule that says: If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc. For example, if k divided by 5 leaves a remainder of 1, then the possible values of k are: 1, 1+5, 1+(2)(5), 1+(3)(5), ...” 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
Brent@GMATPrepNow posted a reply to When Leo imported a certain item, he paid a 7 percent import in the Problem Solving forum
“Here''s a step-by-step algebraic solution. Let T = the TOTAL value of the item. Leo paid a 7% import tax on the portion of the total value of the item in EXCESS of $1000 So, Leo pays tax on the amount that''s GREATER then$1000 So, Leo pays 7% tax on (T - 1000) We can write: import tax = ...”
November 13, 2018
Brent@GMATPrepNow posted a reply to If xy ≠ 0 and x^2+4y^2=4xy, (x+y)/(x-y)=? in the Problem Solving forum
“GIVEN: x² + 4y² = 4xy Subtract 4xy from both sides to get: x² - 4xy + 4y² = 0 Factor left side to get: (x - 2y)(x - 2y) = 0 So, we can conclude that (x - 2y) = 0, which means x = 2y Now take (x+y)/(x-y) and replace x with 2y to get: (x + y)/(x - y) = (2y + y)/(2y - y) = 3y/y = 3 ...”
November 13, 2018
Brent@GMATPrepNow posted a reply to OG #217 question in the Problem Solving forum
“P(selecting a sibling pair) = P(select a junior with a sibling AND select the senior who is that junior''s sibling) = P(select a junior with a sibling) x P(select the senior who is that junior''s siblingx 1/800 = 60/800,000 = 3/40,000 = A Note: P(select a junior with a sibling) = 60/1000, ...”
November 12, 2018
Brent@GMATPrepNow posted a reply to In the figure AB and CD are two diameters of circle. in the Problem Solving forum
“Let''s use some useful circle properties First let''s add a blue line, to divide ∠CEB into 2 angles https://i.imgur.com/xe05QIU.png CD is the DIAMETER of the circle Since ∠CED is an inscribed angle containing (aka "holding") the diameter, we can conclude that ∠CED = 90° ...”
November 12, 2018
Brent@GMATPrepNow posted a reply to Is the tallest child in Class A taller than tallest child in in the Data Sufficiency forum
“Target question: Is the tallest child in Class A is taller than tallest child in Class B? Jump to . . . Statements 1 and 2 COMBINED There are several scenarios that satisfy BOTH statements. Here are two: Case a: Class A heights = {1, 50} and Class B heights = {2, 40}. In this case, the ...”
November 12, 2018
Brent@GMATPrepNow posted a reply to Eight women and two men are available to serve on a in the Problem Solving forum
“When it comes to probability questions involving "at least," it''s best to try using the complement. That is, P(Event A happening) = 1 - P(Event A not happening) So, here we get: P(getting at least 1 man) = 1 - P(not getting at least 1 man) What does it mean to not get at least 1 man? ...”
November 11, 2018
Brent@GMATPrepNow posted a reply to If the positive integer n is greater than 6, what is the in the Data Sufficiency forum
“Here''s a somewhat long approach (but it works!): Target question: What is the remainder when n is divided by 6? Given: Positive integer n is greater than 6 Statement 1: When n is divided by 9, the remainder is 2. ------ASIDE---------------- When it comes to remainders, we have a ...”
November 11, 2018
Brent@GMATPrepNow posted a reply to If x and y are positive integers, what is the remainder when in the Data Sufficiency forum
“Hi Swerve, To avoid ambiguity, you might want to add some spaces or brackets to the original expression. As it stands, 10^x+y could be interpreted as either 10^(x+y) or (10^x) + y Cheers, Brent”
November 11, 2018
Brent@GMATPrepNow posted a reply to If x and y are positive integers such that x = 8y + 12, what in the Data Sufficiency forum
“Target question: What is the greatest common divisor of x and y? Given: x = 8y + 12 Statement 1: x = 12u, where u is an integer. There are several pairs of values that satisfy the given conditions. Here are two: Case a: x=36 and y=3, in which case the GCD of x and y is 3 Case b: x=60 ...”
November 11, 2018
Brent@GMATPrepNow posted a reply to Which of the following is closest to the value of (2^23) in the Problem Solving forum
“(2^23)(5^26) = (2^23)(5^23)(5^3) = (2^23)(5^23)(5^3) = (10^23)(5^3) = (10^23)(125) ≈ (10^23)(100) ≈(10^23)(10^2) ≈10^25 Answer: C Cheers, Brent”
November 11, 2018
Brent@GMATPrepNow posted a reply to A gardener is going to plant 2 red rosebushes and 2 white in the Problem Solving forum
“We can also apply probability rules: P(2 middle bushes are red) = P(1st bush is white AND 2nd bush is red AND 3rd bush is red AND 4th bush is white) = P(1st bush is white) x P(2nd bush is red) x P(3rd bush is red) x P(4th bush is white) = 2/4 x 2/3 x 1/2 x 1/1 = 1/6 = B Cheers, Brent”
November 11, 2018
Brent@GMATPrepNow posted a reply to A gardener is going to plant 2 red rosebushes and 2 white in the Problem Solving forum
“As with many probability questions, we can also solve this using counting techniques. P(2 middle are red) = (# of outcomes with 2 red in middle)/(total number of outcomes) Label the 4 bushes as W1, W2, R1, R2 total number of outcomes We have 4 plants, so we can arrange them in 4! ways = ...”
November 11, 2018
Brent@GMATPrepNow posted a reply to Of the first three dozen cookies baked at a bake shop on a in the Data Sufficiency forum
“ Given: Of the first three dozen (36) cookies baked at a bake shop on a certain day, 1/3 were chocolate chip cookies. 1/2 of the remaining cookies that were baked that day were chocolate chip cookies, 1/3 of 36 = 12. So, 12 chocolate cookies were baked in the first round of baking. Let x = ...”
November 10, 2018
Brent@GMATPrepNow posted a reply to There were 36,000 hardback copies of a certain novel sold in the Problem Solving forum
“From the time the first paperback copy was sold until the last copy of the novel was sold 9 times as many paperback copies as hardback copies were sold Let x = number of hardback copies sold during this time So 9x = number of paperback copies sold during this time So, x + 9x = total number of ...”
November 10, 2018
Brent@GMATPrepNow posted a reply to A box contains 10 balls numbered from 1 to 10 inclusive. If in the Problem Solving forum
“P(Ann and Jane remove same ball) = P(Ann removes ANY ball AND Jane''s ball matches Ann''s ball) = P(Ann removes ANY ball) x P(Jane''s ball matches Ann''s ball) = 1 x 1/10 = 1/10 Answer: D Aside: Once Jane removes her ball (and then replaces it), we have 10 balls, and 1 of them is the one ...”
November 10, 2018
Brent@GMATPrepNow posted a reply to If CD = 6, what is the length of BC? in the Data Sufficiency forum
“Is there an image? Cheers, Brent”
November 9, 2018
Brent@GMATPrepNow posted a reply to Andrew has a certain number of coins in his pocket. He has in the Problem Solving forum
“Let x = number of QUARTERS in pocket So, 0.25x = VALUE of quarters in pocket He has three times as many dimes as quarters So, 3x = number of DIMES in pocket So, 0.10(3x) = 0.3x = VALUE of dimes in pocket He has six times as many nickels as dimes. So, (6)(3x) = number of NICKELS in ...”
November 8, 2018
Brent@GMATPrepNow posted a reply to Challenge: Al, Bob, Cal and Don each own 1 hat. If the 4... in the Problem Solving forum
“I created this question to highlight many students'' tendency to avoid listing and counting as a possible approach. As you''ll see, the approach is probably the fastest approach. P(no one receives his own hat) = (# of outcomes in which no one receives his own hat)/(TOTAL number of outcomes) ...”
November 8, 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
Brent@GMATPrepNow posted a reply to There are 27 different three-digit integers that can be in the Problem Solving forum
“Yes, great work, Mitch! I thought I''d mention that, once we know the correct answer is a multiple of 222 (which is also a multiple of 3), then the correct answer will be a multiple of 3. Useful property: If a number is a multiple of 3, then the sum of its digits is also a multiple of 3. When we ...”
November 7, 2018
Brent@GMATPrepNow posted a new topic called Challenge: Al, Bob, Cal and Don each own 1 hat. If the 4... in the Problem Solving forum
“Al, Bob, Cal and Don each own 1 hat. If the 4 hats are randomly distributed so that each man receives exactly 1 hat, what is the probability that no one receives his own hat? A) 1/8 B) 1/4 C) 1/3 D) 3/8 E) 1/2 Answer: D Difficulty level: 650 – 700 Source: www.gmatprepnow.com”
November 7, 2018
Brent@GMATPrepNow posted a reply to If x, y and z are non-negative integers such that x < y & in the Problem Solving forum
“I created this question to show that there can be times when the best (i.e., fastest) way to solve a counting question is by listing and counting How do we know when it''s not a bad idea to use listing and counting? The answer choices will tell us (ALWAYS scan the answer choices before ...”
November 7, 2018
Brent@GMATPrepNow posted a reply to How many men are in a certain company's vanpool program? in the Data Sufficiency forum
“Target question: How many men are in a certain company''s vanpool program? Statement 1: The ratio of men to women in the program is 3 to 2. Let''s TEST some values. There are several scenarios that satisfy statement 1. Here are two: Case a: There are 3 men and 2 women in the program. In ...”
November 7, 2018
Brent@GMATPrepNow posted a reply to Speed Time Distance MGMAT in the Problem Solving forum
“GIVEN: When the men start walking, Brian has a 30-mile lead Let B = Brian''s walking speed (in miles per hour) Let A = Ashok''s walking speed (in miles per hour) Since Ashok''s speed is greater than Brian''s speed, the rate at which the gap shrinks = (A - B) miles per hour For example, if A ...”
November 6, 2018
Brent@GMATPrepNow posted a reply to 2019 GMAC Official Guide applicable for 60-Day Study Guide? in the The 60-Day GMAT Study Guide forum
“If you go here (https://www.gmatprepnow.com/content/improvement-chart) and download the Improvement Chart for the OG2016, you''ll see the question breakdown for each topic. This should help. Cheers, Brent”
November 6, 2018
Brent@GMATPrepNow posted a reply to In a certain game, a large bag is filled with blue, green, in the Problem Solving forum
“This question begs for some prime factorization. 88,000 = (2)(2)(2)(2)(2)(2)(5)(5)(5)(11) First, we can see that there must be one (11-point) red chip. Now, what role do these 2''s play? Since there are no 2''s hiding among the 5-point chips or the 11-point chips, the 2''s must be associated ...”
November 6, 2018
Brent@GMATPrepNow posted a reply to [x] is the greatest integer less than or equal x, what is th in the Problem Solving forum
“GIVEN: For example, [3.2] = 3, since 3 is the greatest integer that is less than (or equal) to 3.2 Likewise, [8.7] = 8, since 8 is the greatest integer that is less than (or equal to) 8.7 Now onto the question.... √25 = 5 √36 = 6 √49= 7 √64 = 8 Since √30 is BETWEEN √25 ...”
November 6, 2018
Brent@GMATPrepNow posted a reply to If in k+1 years from now John will be m years old, then how in the Problem Solving forum
“In k+1 years from now John will be m years old So, m - (k + 1) = John''s PRESENT age How old was John t-1 years ago? So, m - (k + 1) - (t - 1) = John''s age (t-1) YEARS AGO Simplify m - (k + 1) - (t - 1) to get: m - k - t Answer: A Cheers, Brent”
November 6, 2018
Brent@GMATPrepNow posted a reply to Pipe A runs 30 liters of water per minute into a pool that in the Problem Solving forum
“Let''s determine the COMBINED RATE of the two pipes Given: Pipe A''s RATE = 30 liters per minute This is equivalent to 1800 liters per HOUR Pipe B fills a third of the pool in 6 hours So, Pipe B fills the ENTIRE pool (3600 liters) in 18 hours Rate = Output/time = 3600/18 = 200 liters ...”
November 6, 2018
Brent@GMATPrepNow posted a new topic called If x, y and z are non-negative integers such that x < y < z, in the Problem Solving forum
“If x, y and z are non-negative integers such that x < y < z, then the equation x + y + z = 11 has how many distinct solutions? A) 5 B) 10 C) 11 D) 22 E) 78 Answer: B Difficulty level: 600-650 Source: www.gmatprepnow.com”
November 5, 2018
Brent@GMATPrepNow posted a reply to Challenge question: Is |1 - 4k| < k? in the Data Sufficiency forum
“Target question: Is |1 - 4k| < k? Statement 1: k > 4x³ This pretty much tells is that k can have ANY value. For example, notice that, if x = -100, then 4x³ = -4,000,000 So, for this value of x, k can be any number greater than -4,000,000 Let''s TEST some values. There are ...”
November 5, 2018
Brent@GMATPrepNow posted a reply to Which sport utility vehicle has a higher list price, the in the Data Sufficiency forum
“Target question: Which sport utility vehicle has a higher list price, the Touristo of the Leisure? Statement 1: The list price of the Leisure is 5/6 the list price of the Touristo. If the Leisure''s price is 5/6 of the Touristo''s price, then the answer to the target question is the Touristo ...”
November 5, 2018
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“Here''s our video on Range and Standard Deviation https://www.youtube.com/watch?v=FbAlIjw2fwY Cheers, Brent”
November 5, 2018
Brent@GMATPrepNow posted a reply to If xy=-18, is x less than y? in the Data Sufficiency forum
“ Given: xy = -18 Target question: is x less than y? Statement 1: x < 0 In other words, x is NEGATIVE So, our given information (xy = -18) becomes: (NEGATIVE)(y) = -18 In other words: (NEGATIVE)(y) = NEGATIVE This tells us that y is POSITIVE If y is POSITIVE, and x is NEGATIVE, the ...”
November 4, 2018
Brent@GMATPrepNow posted a reply to Challenge #2: If x and y are different positive integers, wh in the Problem Solving forum
“i) When x is divided by y, the remainder is 2x The remainder cannot be greater than the dividend (the number we''re dividing) For example, it CANNOT be the case that 17 divided by 5 leaves a remainder of 34 Statement i can never be true Check the answer choices. . . . ELIMINATE A and D ii) ...”
November 3, 2018
Brent@GMATPrepNow posted a new topic called Challenge question: Is |1 - 4k| < k? in the Data Sufficiency forum
“Is |1 - 4k| < k? (1) k > 4x³ (2) k < 2x – x² - 2 Answer: B Difficulty level: 700+ Source: www.gmatprepnow.com”
November 3, 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
Brent@GMATPrepNow posted a reply to If the average (arithmetic mean) of p, q, and r is 6, what i in the Data Sufficiency forum
“ Given: The average (arithmetic mean) of p, q, and r is 6 We can write: (p + q + r)/3 = 6 This means: p + q + r = 18 Target question: What is the value of r? Statement 1: p = -r Given: p + q + r = 18 Replace p with -r to get: -r + q + r = 18 Simplify: q = 18 What about the value of ...”
November 2, 2018
Brent@GMATPrepNow posted a reply to Cars J and K are making the trip from City A to City B. in the Problem Solving forum
“Car K travels at a constant speed that is 80% the constant speed of Car J Let''s assign some nice values to the speeds. Let''s say Car J travels 40 miles per hour So, Car K travels 32 miles per hour Car J departs from City A 15 minutes after Car K does Let''s calculate the distance that Car ...”
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
Brent@GMATPrepNow posted a reply to At a family summer party, each of the x members of the in the Problem Solving forum
“Let''s use the INPUT-OUTPUT approach. It might be useful to choose a number that works well with the fractions given in the question (1/3 and 1/7). So, let''s say there are 21 family members at the party. In other words, we''re saying that x = 21 1/3 chose to have a hamburger, and of ...”
November 1, 2018
Brent@GMATPrepNow posted a reply to When a positive integer n is divided by 19, what is the rema in the Data Sufficiency forum
“Target question: When n is divided by 19, what is the remainder? Statement 1: n-17 is a multiple of 19 ----ASIDE------------------------------------------- If N is a multiple of d, then we can write N = dk (for some integer k) For example, if N is a multiple of 5, then we can write N = 5k ...”
November 1, 2018
Brent@GMATPrepNow posted a reply to In the diagram above, points A, B, C, D, and E represent the in the Problem Solving forum
“points A, B, C, D, and E represent the five teams in a certain league in which each team must play each of the other teams exactly once. Let''s first determine the total number of games that will be played. There are 5 teams, so each team will play 4 games (since a team can''t play itself) So, ...”
November 1, 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
Brent@GMATPrepNow posted a reply to In four years, Andy will be twice as old as Betsy. How old in the Data Sufficiency forum
“ Given: In four years, Andy will be twice as old as Betsy. Let A = Andy''s PRESENT age Let B = Betsy''s PRESENT age So, A+4 = Andy''s age IN 4 YEARS And so, B+4 = Betsy''s age IN 4 YEARS If Andy will be twice as old as Betsy IN 4 YEARS, we can write: A+4 = 2(B+4) Expand: A + 4 = 2B + 8 ...”
October 31, 2018
Brent@GMATPrepNow posted a reply to If m and n are integers, is m+m^2-n an even number? in the Data Sufficiency forum
“ Given: m and n are integers Target question: Is m + m² - n an even number? This is a good candidate for rephrasing the target question Aside: Here’s a video with tips on rephrasing the target question: We can take the expression, m + m² - n and rewrite it as m(1 + m) - n Now notice ...”
October 31, 2018
Brent@GMATPrepNow posted a reply to In 1995 a certain store had 1,800 tools in stock that had in the Problem Solving forum
“1,000 of these tools were sold in 1995 for $40 each So, the REVENUE = (1000)($40) = $40,000 The 1000 tools were purchased for$30 each. So, the EXPENSE = (1000)($30) =$30,000 PROFIT for 1995 = $40,000 -$30,000 = $10,000 ----------------------------------------------- The remaining 800 ...” October 31, 2018 Brent@GMATPrepNow posted a reply to Tom, Bill, Robert, Roger, and Terry are standing in a row in the Problem Solving forum “One approach is to ignore the rule and determine the total number of ways to arrange all 5 people, and then subtract the number of arrangements that BREAK the rule. I''m sure someone will post that kind of solution shortly. Here''s another approach: Take the task of arranging the 5 men and ...” October 30, 2018 Brent@GMATPrepNow posted a new topic called Challenge #2: If x and y are different positive integers, wh in the Problem Solving forum “If x and y are different positive integers, which of the following COULD be true: i) When x is divided by y, the remainder is 2x ii) When x is divided by 2y, the remainder is y iii) When (2x + y) is divided by (x + y), the remainder is y A) i only B) ii only C) iii only D) i & ii ...” October 30, 2018 Brent@GMATPrepNow posted a reply to Challenge: If x and y are different positive integers, which in the Problem Solving forum “i) When x is divided by y, the remainder is x This occurs any time x < y For example, if x = 5 and y = 7, then statement i becomes: When 5 is divided by 7, the remainder is 5 So true! Scan the answer choices....eliminate D ----------------------------------------------------- ii) When 2x ...” October 30, 2018 Brent@GMATPrepNow posted a reply to Carmelo and LeBron participate in a seven-person footrace on in the Problem Solving forum “Here are three similar questions to practice with: - http://www.beatthegmat.com/counting-six-mobsters-t47167.html - http://www.beatthegmat.com/permutation-and-combination-t273916.html - http://www.beatthegmat.com/permutations-with-waiting-line-t274020.html Cheers, Brent” October 30, 2018 Brent@GMATPrepNow posted a reply to A certain basket contains 10 apples, 7 of which are red and in the Problem Solving forum “Jay has demonstrated a solution that involves counting techniques. Here''s one that involves probability rules. Let''s find the probability of selecting a red apple 1st, a red apple 2nd, and a green apple 3rd (aka RRG) P(red apple 1st AND red apple 2nd AND green apple 3rd) = P(red apple 1st) x ...” October 30, 2018 Brent@GMATPrepNow posted a reply to A salesperson for an automobile dealer earns an annual in the Problem Solving forum “Total earnings = (base salary) + (commission) base salary =$25,000 commission = 10% of total sales OVER $100,000 = 10% of (x -$100,000) = 0.1(x - $100,000) So, total earnings =$25,000 + 0.1(x - $100,000) Answer: E Cheers, Brent” October 30, 2018 Brent@GMATPrepNow posted a reply to There are 16 teams in a soccer league, and team plays each in the Problem Solving forum “Another approach: The question is really asking, "In how many different ways can we create 2-team pairings from 16 teams?" Since the order of the selections does not matter (i.e., selecting teams A and B to play, is the same as selecting teams B and A to play), we can use combinations. ...” October 30, 2018 Brent@GMATPrepNow posted a reply to There are 16 teams in a soccer league, and team plays each in the Problem Solving forum “There are 16 teams. If we ask each team, "How many teams did you play?" we''ll find that each team played 15 teams, which gives us a total of 240 games (since 16 x 15 = 240). From here we need to recognize that each game has been COUNTED TWICE. For example, if Team A and Team B play ...” October 30, 2018 Brent@GMATPrepNow posted a reply to For integers a, b, c, a/(b - c)=1 what is the value of (b-c) in the Data Sufficiency forum “ Given: a/(b - c) = 1 Target question: What is the value of (b-c)/b ? This is a good candidate for rephrasing the target question. Aside: Here’s a video with tips on rephrasing the target question: If a/(b - c) = 1, then we know that a = b - c The target question asks "What is the ...” October 29, 2018 Brent@GMATPrepNow posted a reply to If a and b are integers such that a > b > 1, which of in the Problem Solving forum “Let''s make an important observation. Some positive multiples of 3 are: 3, 6, 9, 12, . . . . Some positive multiples of 5 are: 5, 10, 15, 20, . . . . Some positive multiples of 12 are: 12, 24, 36, 48, . . . . General observation: the positive multiples of k are all greater than or equal to k ...” October 29, 2018 Brent@GMATPrepNow posted a new topic called Challenge: If x and y are different positive integers, which in the Problem Solving forum “If x and y are different positive integers, which of the following COULD be true: i) When x is divided by y, the remainder is x ii) When 2x is divided by y, the remainder is x iii) When x+y is divided by x , the remainder is x-y A) i only B) i & ii only C) i & iii only D) ii & ...” October 29, 2018 Brent@GMATPrepNow posted a reply to What is the value of x? in the Data Sufficiency forum “Target question: What is the value of x? Statement 1: (x + 2)(x + 3) = 0 This means that EITHER x = -2 OR x = -3 Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT Statement 2: x² + 5x + 6 = 0 Factor the left side of the equation to get: (x + 2)(x ...” October 29, 2018 Brent@GMATPrepNow posted a reply to A length of rope is cut into three different lengths. What in the Data Sufficiency forum “Target question: What is the length of the shortest rope? Let''s assign some variables. Let x = length of shortest rope Let y = length of middle rope Let z = length of longest rope Statement 1: The combined length of the longest two pieces is 6 feet. In other words, y + z = 6 Since we ...” October 28, 2018 Brent@GMATPrepNow posted a reply to Challenge question: At noon, Joe and a hummingbird leave in the Problem Solving forum “The main idea here is that all 3 travelers travel for the SAME amount of time. So, let''s first determine the time it takes for Joe and Sue to meet. This is a shrinking gap question. To determine the rate at which the gap shrinks, we''ll ADD the travel speeds of Joe and Sue That is, ...” October 28, 2018 Brent@GMATPrepNow posted a reply to If x and y are positive, what is the value of y ? in the Data Sufficiency forum “Target question: What is the value of y? Given: x and y are positive Statement 1: xy is the square of an integer. There are several values of x and y that satisfy this condition. Here are two: Case a: x = 1 and y = 1. Here xy = (1)(1) = 1, which is the square of an integer. In this ...” October 28, 2018 Brent@GMATPrepNow posted a new topic called Challenge question: At noon, Joe and a hummingbird leave in the Problem Solving forum “At noon, Joe and a hummingbird leave point A and travel towards point B, which is 12 miles away. At the same time Sue leaves point B and travels toward point A. Joe, Sue and the hummingbird travel at constant speeds of 3 miles per hour, 4 miles per hour, and 84 miles per hour respectively. When the ...” October 27, 2018 Brent@GMATPrepNow posted a reply to There are n students in a class. Of them, k boys and k girls in the Data Sufficiency forum “Target question: What is the probability that Harvey will be paired with Jessica? Given: There are n students in a class. Of them, k boys and k girls (including Harvey and Jessica) are selected for a dance performance in which students will dance in pairs of one boy and one girl. ...” October 27, 2018 Brent@GMATPrepNow posted a reply to When the positive integer n is divided by 25, the remainder in the Data Sufficiency forum “Target question: What is the value of n? Given: When the positive integer n is divided by 25, the remainder is 13. -------ASIDE------------- When it comes to remainders, we have a nice rule that says: If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, ...” October 27, 2018 Brent@GMATPrepNow posted a reply to A circus clown is entertaining kids by making balloon in the Problem Solving forum “As with many probability questions, we can solve this by using counting techniques or rules of probability. Let''s use rules of probability P(balloon animal is an elephant) = 1/4 P(balloon animal is purple) = 1/5 P(clown makes a purple elephant balloon animal) = P(balloon animal is ...” October 27, 2018 Brent@GMATPrepNow posted a reply to In a right triangle, the longer leg is two more than three in the Problem Solving forum “In a right triangle, the longest side is called the hypotenuse, and the two sides that meet to create a 90-degree angle are called the legs. So, one leg will be the triangle''s base, and the other leg will be the triangle''s height. Let x = length of the triangle''s base (which, for this ...” October 27, 2018 Brent@GMATPrepNow posted a reply to If a and b are two positive numbers, what is the product of in the Data Sufficiency forum “Target question: What is the value of ab? Statement 1: The LCM of a and b is 16 Let''s TEST some values. There are several values of a and b that satisfy statement 1. Here are two: Case a: a = 1 and b = 16 (the LCM of 1 and 16 is 16). In this case, the answer to the target question is ab = ...” October 26, 2018 Brent@GMATPrepNow posted a reply to In the mid-1960's a newly installed radar warning system in the Sentence Correction forum “The idiom here is "Mistake x FOR y" So, we can eliminate A, C and E We''re left with B and D D conveys an ambiguous message, because it suggests that the moon was rising for an attack. ELIMINATE D Answer: B Cheers, Brent” October 26, 2018 Brent@GMATPrepNow posted a reply to What is the largest prime factor of the expression 3^8 − 2 in the Problem Solving forum “There''s a difference of squares "hiding" in the expression 3^8 − 2^12 That is 3^8 − 2^12 = (3^4)² − (2^6)² We know that: x² - y² = (x + y)(x - y) So, we get: (3^4)² − (2^6)² = (3^4 + 2^6)(3^4 - 2^6) = (81 + 64)(81 - 64) = (145)(17) = (5)(29)(17) The greatest ...” October 26, 2018 Brent@GMATPrepNow posted a reply to When Q is divided by W, the quotient is R and the remainder in the Problem Solving forum “-----ASIDE----------------------- There''s a nice rule that says, "If N divided by D equals Q with remainder R, then N = DQ + R" For example, since 17 divided by 5 equals 3 with remainder 2, then we can write 17 = (5)(3) + 2 Likewise, since 53 divided by 10 equals 5 with remainder 3, ...” October 26, 2018 Brent@GMATPrepNow posted a reply to Tricky: If AB || DE, and AB = 10, what is the length of DE? in the Data Sufficiency forum “Let''s first add the given information (and their implications) to the diagram If AB || DE, we know that ∠BAC = ∠CED and ∠ABC = ∠DCE Also, since vertically opposite angles are equal, we know that ∠ACB = ∠DCE https://i.imgur.com/fgDp7Yh.png Now that we''ve identified 3 pairs of ...” October 26, 2018 Brent@GMATPrepNow posted a new topic called Tricky: If AB || DE, and AB = 10, what is the length of DE? in the Data Sufficiency forum “https://i.imgur.com/jyTAK6n.png If AB || DE, and AB = 10, what is the length of DE? (1) BC = 6 and CE = 4 (2) DC = 3 and CB = 6 Answer: B Difficulty level: 650 – 700 Source: www.gmatprepnow.com” October 25, 2018 Brent@GMATPrepNow posted a reply to If |x-6|=2x, then x=? in the Problem Solving forum “There are 3 steps to solving equations involving ABSOLUTE VALUE: 1. Apply the rule that says: If |x| = k, then x = k or x = -k 2. Solve the resulting equations 3. Plug solutions into original equation to check for extraneous roots Step 1: x - 6 = 2x or x - 6 = -2x case a: x - 6 = 2x Step ...” October 25, 2018 Brent@GMATPrepNow posted a reply to CHALLENGE: 10 teams (A, B, C, D, E, F, G, H, I and J) partic in the Problem Solving forum “First determine the TOTAL number of games played. We can select 2 teams from 10 teams in 10C2 ways (= 45 ways) So, there will be 45 games in TOTAL IMPORTANT: Each team plays 9 games For each game, 2 points are awarded. So, the TOTAL number of POINTS awarded = (2)(45) = 90 Teams A, B, C, ...” October 24, 2018 Brent@GMATPrepNow posted a reply to Noelle walks from point A to point B at an average speed of in the Problem Solving forum “For these kinds of questions, I typically follow the approach that Fabio used (assign a nice value to the distance). But we can also solve the question algebraically: Let d = the distance between Points A and B. Let x = the Noelle''s speed from Point B to Point A. We want the average ...” October 24, 2018 Brent@GMATPrepNow posted a reply to What is the median number of employees assigned per project in the Data Sufficiency forum “Target question: What is the median number of employees assigned per project? Statement 1: 25 percent of the projects at Company Z have 4 or more employees assigned to each project. Let''s pretend that there are 4 projects altogether. There are several sets of values that meet this condition. ...” October 24, 2018 Brent@GMATPrepNow posted a reply to In a certain company, the ratio of the number of manager to in the Problem Solving forum “One option is to use TWO VARIABLES Let M = CURRENT # of managers Let W = CURRENT # of production-line workers The ratio of the number of managers to the number of production-line workers is 5 to 72. So, we can write: M/W = 5/72 Cross multiply to get: 5W = 72M If 8 additional ...” October 23, 2018 Brent@GMATPrepNow posted a reply to When 100 is divided by positive integer x, the remainder is in the Problem Solving forum “A fast approach is to find a value of x that meets the given condition: When 100 is divided by positive integer x, the remainder is 2 Well, x = 98 satisfies that condition, since 100 divided by 98 = 1 with remainder 2 What is the remainder when 198 is divided by x? Well, 198 divided by 98 ...” 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 “"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 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 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 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Range and Standard Deviation Video: https://www.youtube.com/watch?v=FbAlIjw2fwY Cheers, Brent” October 23, 2018 Brent@GMATPrepNow posted a reply to Which of the following values, when inserted into the set of in the Problem Solving forum “Let''s test each answer choice.... A. 2 The new set becomes {2, 5, 10, 12, 13, 17, 22, 22} Since we have an EVEN number of values in the set, the median equals the average of the two middlemost numbers. So, median = (12 + 13)/2 = 25/2 = 12.5 No good - we want the median to be 15 B. ...” October 23, 2018 Brent@GMATPrepNow posted a reply to What are the coordinates of point B in the figure above ? in the Data Sufficiency forum “IMPORTANT: For geometry Data Sufficiency questions, we are typically checking to see whether the statements "lock" a particular angle, length, or shape into having just one possible measurement. This concept is discussed in much greater detail in the video below. Target question: What ...” October 23, 2018 Brent@GMATPrepNow posted a reply to The range of set A is 24 and the range of set B is 20. What in the Problem Solving forum “If the range of set A is 24, and we add more values (from set B) to set A, then the range of the resulting set must be greater than or equal to 24 (that is, the range of a set cannot get smaller upon adding MORE numbers to that set). For this reason, we can ELIMINATE answer choice A. From ...” October 23, 2018 Brent@GMATPrepNow posted a reply to If x and y are positive integers, what is the remainder when in the Data Sufficiency forum “ Given: x and y are positive integers Target question: What is the remainder when x^y is divided by 10? This is a good candidate for rephrasing the target question. Notice that 43 divided by 10 leaves remainder 3, and 127 divided by 10 leaves remainder 7, and 618 divided by 10 leaves ...” October 23, 2018 Brent@GMATPrepNow posted a new topic called CHALLENGE: 10 teams (A, B, C, D, E, F, G, H, I and J) partic in the Problem Solving forum “10 teams (A, B, C, D, E, F, G, H, I and J) participate in a soccer tournament in which each team plays every other team once. For each game played, points are awarded to the teams as follows: 0 points for losing the game 1 point each for tying the game 2 points for winning the game After ...” October 22, 2018 Brent@GMATPrepNow posted a reply to Clarissa will create her summer reading list by randomly in the Problem Solving forum “Take the task of creating the reading list and break it into stages. Stage 1: Select a book to read 1st There are 10 books to choose from. So, we can complete stage 1 in 10 ways Stage 2: Select a book to read 2nd There are 9 books remaining to choose from (since we already chose a book ...” October 22, 2018 Brent@GMATPrepNow posted a reply to A jar contains only green pencils and red pencils. If the in the Data Sufficiency forum “Target question: What percentage of the pencils are green? Given: The jar contains only green pencils and red pencils. Statement 1: The jar contains 75 red pencils. If 75 of the 225 pencils are red, then the remaining 150 pencils are GREEN. 150/225 = 2/3 = 66 2/3%, so the answer to ...” October 22, 2018 Brent@GMATPrepNow posted a reply to Challenge Question: In the x-y coordinate plane, does line k in the Data Sufficiency forum “Target question: Does line k have a positive x-intercept? Statement 1: (slope of line k)(y-intercept of line k) > 0 There are two possible cases that that satisfy statement 1: - the slope and y-intercept are both positive - the slope and y-intercept are both negative Let''s examine ...” October 21, 2018 Brent@GMATPrepNow posted a reply to What is the area of the triangle formed by the intersection in the Problem Solving forum “Here''s a similar question to practice with: https://www.beatthegmat.com/area-of-triangle-formed-by-intersections-of-3-lines-t276079.html Cheers, Brent” October 21, 2018 Brent@GMATPrepNow posted a new topic called Challenge Question: In the x-y coordinate plane, does line k in the Data Sufficiency forum “In the x-y coordinate plane, does line k have a positive x-intercept? (1) (slope of line k)(y-intercept of line k) > 0 (2) (slope of line k) - (y-intercept of line k) < 0 Answer: A Difficulty level: 650 – 700 Source: www.gmatprepnow.com” October 19, 2018 Brent@GMATPrepNow posted a reply to When positive integer N is divided by positive integer J, in the Problem Solving forum “ASIDE: 7/2 = 3 1/2 = 3 + 0.5 = 3.5 Notice that 1 is the remainder when we divide 7 by 2. 23/5 = 4 3/5 = 4 + 0.6 = 4.6 Notice that 3 is the remainder when we divide 23 by 5. 31/4 = 7 3/4 = 7 + 0.75 = 7.75 Notice that 3 is the remainder when we divide 31 by 4. GIVEN: N/J = 134.08 This means ...” October 19, 2018 Brent@GMATPrepNow posted a reply to If there are more than two numbers in a certain list, is in the Data Sufficiency forum “[quote="Jay@ManhattanReview"] Hey Jay, I thought I should point out that case 2 doesn''t satisfy the statement. If we choose 1 and 2 from the set, then the product isn''t 0. That said, {0, 0, 0, 0, 1} meets the given condition, as does {0, 0, 0, 0, 0, 0, 0, 3} etc Cheers, ...” October 19, 2018 Brent@GMATPrepNow posted a reply to If -1<x<0, Which of the following is listed in ascendi in the Problem Solving forum “Let''s test a value of x. If -1 < x < 0, then x COULD equal -1/2 So, x^(-1) = (-1/2)^(-1) = 1/(-1/2) = -2 And, x^(-2) = (-1/2)^(-2) = 1/(-1/2)^2 = 1/(1/4) = 4 And, x^2 = (-1/2)^2 = 1/4 Listed in ascending order, we get: -2, 1/4, 4 In other words, x^(-1), x^2, x^(-2) Answer: A ...” October 19, 2018 Brent@GMATPrepNow posted a reply to The latest model of space shuttle can achieve a maximum in the Problem Solving forum “GIVEN: The shuttle can travel 25 miles in 1 second So, the shuttle can travel 1500 miles in 60 seconds In other words, the shuttle can travel 1500 miles in 1 MINUTE So, the shuttle can travel 90,000 miles in 60 MINUTES In other words, the shuttle can travel 90,000 miles in 1 HOUR In other ...” October 18, 2018 Brent@GMATPrepNow posted a reply to A jar contains 6 red marbles and 9 blue marbles. If Evelyn in the Problem Solving forum “P(both are same color) = P(1st marble is red AND 2nd marble is red OR 1st marble is blue AND 2nd marble is blue) = x P(2nd marble is red)] + x P(2nd marble is blue)] = x 5/14] + x 8/14] = x 5/14] + x 8/14] = 10/70 + 24/70 = 34/70 = 17/35 Answer: D Cheers, Brent” October 18, 2018 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Time management strategy for test day Video: https://www.youtube.com/watch?v=bWrUiBT83PQ Cheers, Brent” October 18, 2018 Brent@GMATPrepNow posted a reply to In the x-y coordinate plane, line k passes through in the Problem Solving forum “Notice that, if the line passes through the origin, then the line has slope -4/5 (aka a slope of -0.8), but the line will not have a negative x-intercept Notice that, if the line passes through the (0,4), then the line will have slope 0, BUT the line will not have a negative x-intercept. See ...” October 18, 2018 Brent@GMATPrepNow posted a reply to f[f{f(x)}]=??? in the GMAT Math forum “Useful property: 1/(a/b) = b/a We want: ff(5)}] = f1/6}] f{1/6} = 1/(1 + 1/6) = 1/(7/6) = 6/7 So, ff{1/6}] = f6/7] Finally, f[6/7] = 1/(1 + 6/7) = 1/(13/7) = 7/13 Answer: B (since 21/39 reduces to the equivalent fraction 7/13) Cheers, Brent” October 18, 2018 Brent@GMATPrepNow posted a reply to In the month of August, Pentheus Corporation made$200,000 in the Problem Solving forum
“In the month of August, Pentheus Corporation made $200,000 in profit. Pentheus made 6% of that profit on the second Wednesday of August. 1% of$200,000 = $2,000, so 6% of$200,000 = (6)($2,000) =$12,000 So, the profit on that day = $12,000 If the profits that day were approximately 14.5% of ...” October 18, 2018 Brent@GMATPrepNow posted a reply to Brian purchased a bouquet of 40 flowers for his mother for in the Problem Solving forum “We can solve this question using either 1 variable or 2 variables. Here''s an approach that involves 1 variable: Let t = # of tulips in bouquet So. 40 - t = # of roses in bouquet So, ($1.00)(t) = the total COST of all t tulips And ($1.50)(40 - t) = the total COST of all 40-t roses ...” October 18, 2018 Brent@GMATPrepNow posted a reply to In a town of 8,000 residents, 65 percent of all residents in the Problem Solving forum “Another approach is to use the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it (aka overlapping sets questions). Here, we have a population of residents, and the two characteristics are: ...” October 17, 2018 Brent@GMATPrepNow posted a reply to What is the remainder if 7^10 is divided by 100? in the Problem Solving forum “Sweeeeeeeeeeeeet solution, Scott!! Cheers, Brent” October 17, 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 Brent@GMATPrepNow posted a reply to If x, y, and z are all nonzero numbers, and x = y + z, which in the Problem Solving forum “NOTE: this is one of those questions that require us to check/test each answer choice. In these situations, always check the answer choices from E to A, because the correct answer is typically closer to the bottom than to the top. For more on this strategy, see my article: ...” 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 Brent@GMATPrepNow posted a reply to Set X consists of different positive numbers arranged in in the Data Sufficiency forum “Target question: What is the arithmetic mean of set X? Given: Set X consists of different positive numbers arranged in ascending order: K, L, M, 5, 7. K, L and M are consecutive integers This means that EITHER K, L, M = 1, 2, 3 respectively, OR K, L, M = 2, 3, 4 respectively Head straight ...” October 16, 2018 Brent@GMATPrepNow posted a reply to A Martian bat flies at 60 yards per second from its nest to in the Problem Solving forum “Rich''s approach is definitely the best (i.e., fastest) way to solve this question. However, if the answer choices weren''t so sweet, here''s an algebraic solution Average speed = (total distance traveled)/(total travel time) Let''s assign nice values to the distances. These values should ...” October 16, 2018 Brent@GMATPrepNow posted a reply to Charlie takes 2.5 hours to fly from Los Angeles to Mexico in the Problem Solving forum “Average speed = (total distance traveled)/(total travel time) So, Average speed = 1200/2.5 = 2400/5 = 4800/10 = 480 mph Answer: D Cheers, Brent” October 16, 2018 Brent@GMATPrepNow posted a reply to A certain NYC taxi driver has decided to start charging a in the Problem Solving forum “Here''s an algebraic approach: A certain taxi driver charges a rate of r CENTS per person per mile r CENTS = r/100 DOLLARS Since there are 3 people, the rate is (3)(r/100) DOLLARS per mile In other words, the rate is 3r/100 dollars per mile. With a 50% discount, the new rate = ...” October 16, 2018 Brent@GMATPrepNow posted a new topic called In the x-y coordinate plane, line k passes through in the Problem Solving forum “In the x-y coordinate plane, line k passes through the point (5, -4) and has a negative x-intercept. Which of the following COULD be the equation of line k? i) y = -0.4x - 2 ii) y = 2 - 1.2x iii) y = -0.7x - 1.5 A) i only B) ii only C) iii only D) i & ii only E) i & iii only ...” October 16, 2018 Brent@GMATPrepNow posted a reply to Lindsay can paint 1/x of a certain room in one hour. If in the Problem Solving forum “This appears to be a slightly different version of this official question: https://www.beatthegmat.com/work-rate-problem-5-t292679.html HOWEVER, unless I''m missing something, the correct answer is missing. Cheers, Brent” October 15, 2018 Brent@GMATPrepNow posted a reply to How many factors does the number X have? in the Data Sufficiency forum “Target question: How many factors does the number X have? Statement 1: X is divisible by 47 Let''s TEST some values. There are several values of X that satisfy statement 1. Here are two: Case a: X = 47. The factors of 47 are {1, 47}. So, the answer to the target question is X has 2 ...” October 15, 2018 Brent@GMATPrepNow posted a reply to A rectangular solid S, has dimensions 4 by 9 by k. What is in the Data Sufficiency forum “Target question: What is the value of k? Given: A rectangular solid S, has dimensions 4 by 9 by k Statement 1: 4 < k < 9 Since k can have ANY value between 4 and 9, statement 1 is NOT SUFFICIENT Statement 2: A cube of side 6 has the same volume as rectangular solid S. So ...” October 15, 2018 Brent@GMATPrepNow posted a reply to In the rectangular coordinate system above, if the in the Data Sufficiency forum “I think that, if this were an official GMAT question, the correct answer would be E (not B), because we aren''t specifically told that the dotted lines are parallel to the x-axis and the y-axis. If those dotted lines aren''t parallel to those axes, the we can''t determine the value of y. ...” October 15, 2018 Brent@GMATPrepNow posted a reply to In the figure above, triangle ABC is equilateral, and point in the Problem Solving forum “It may help to add some lines to the diagram. First add lines from the center to the 3 vertices. https://s8.postimg.cc/e412m8uq9/clk1.jpg Aside, we know that each angle is 120º since all three (equivalent) angles must add to 360.º Then draw a circle so that the triangles vertices are on ...” October 15, 2018 Brent@GMATPrepNow posted a reply to The mass of 1 cubic meter of a substance is 800 kg under in the Problem Solving forum “GIVEN: 1 cubic METER of the substance weighs 800 KILOGRAMS 1 kg =1,000 grams, so we can write: 1 cubic METER of the substance weighs 800,000 GRAMS 1 cubic meter = 1,000,000, so we can write: 1,000,000 cubic CENTIMETERS of the substance weighs 800,000 GRAMS What is the volume in cubic ...” October 14, 2018 Brent@GMATPrepNow posted a reply to At a family summer party, each of the x members of the in the Problem Solving forum “These kinds of questions (Variables in the Answer Choices - VIACs) can be answered algebraically or using the INPUT-OUTPUT approach. The Ash Mo solved the question algebraically, so let''s use the INPUT-OUTPUT approach. It might be useful to choose a number that works well with the fractions ...” October 13, 2018 Brent@GMATPrepNow posted a reply to When A and B are positive integers, is AB a multiple of 4? in the Data Sufficiency forum “Target question: Is AB a multiple of 4? Useful property: If N is divisible by d, we can say that N = dk for some integer k For example, if N is divisible by 5, we can say that N = 5k for some integer k Statement 1: The greatest common divisor of A and B is 6 This means that A is divisible ...” October 13, 2018 Brent@GMATPrepNow posted a reply to How much time did it take a certain car to travel 400 in the Data Sufficiency forum “Target question: How long did it take to travel 400km To find the travel time, we need to know the average speed traveled. Let x = the average speed traveled. REPHRASED target question: What is the value of x? Statement 1: The car traveled the first 200 km in 2.5 hrs No info about the ...” October 13, 2018 Brent@GMATPrepNow posted a reply to Challenge question: What is the sum of all in the Problem Solving forum “Approach #1 If we recognize that x^(2/3) = u-substitution. Let u = x^(1/3) Now take original equation and replace x^(1/3) with u to get: u² - u - 2 = 4 Subtract 4 from both sides to get: to get: u² - u - 6 = 0 Factor: (u - 3)(u + 2) = 0 So, the two solutions here are u = 3 and u = -2 ...” October 13, 2018 Brent@GMATPrepNow posted a reply to A certain club has 10 members, including Harry. One of the 1 in the Problem Solving forum “As with many probability questions, we can solve this using counting techniques or probability rules. So, before you embark on one approach, try to determine which one is faster. Here''s the probability approach: P(Harry selected Secretary or Treasurer) = 1 - P(Harry selected president OR ...” October 13, 2018 Brent@GMATPrepNow posted a reply to The average age of a group of n people is 15 yrs. One more in the Problem Solving forum “The average age of a group of n people is 15 yrs. So, (sum of all n ages)/n = 15 Multiply both sides by n to get: (sum of all n ages) = 15n One more person aged 39 joins the group and the new average is 17 yrs. IMPORTANT: Once this 39-year-old is added to the group, the (NEW sum of ages) = ...” October 12, 2018 Brent@GMATPrepNow posted a new topic called Challenge question: What is the sum of all in the Problem Solving forum “What is the sum of all solutions to the equation x^(2/3) - x^(1/3) - 2 = 4? A) -35 B) -19 C) 7 D) 19 E) 35 Answer: D Source: www.gmatprepnow.com Difficulty level: 600 - 650” October 12, 2018 Brent@GMATPrepNow posted a reply to Challenge question: j and k are positive integers in the Data Sufficiency forum “ Given: n = 10^j + k Target question: Is n divisible by 15? Key concepts: - If n is divisible by 15, then n must be divisible by 3 AND by 5 - If n is divisible by 3, then the sum of n''s digits must be divisible by 3 (for example, we know that 747 is divisible by 3, because 7+4+7 = 18, ...” October 12, 2018 Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum “Here''s our video on "if" versus "whether" https://www.youtube.com/watch?v=F2ZHtB088us Cheers, Brent” October 11, 2018 Brent@GMATPrepNow posted a new topic called Challenge question: j and k are positive integers in the Data Sufficiency forum “j and k are positive integers, and n = 10^j + k. Is n divisible by 15? (1) j and k are each divisible by 3 (2) j and k are each divisible by 5 Answer: A Difficulty level: 700+ Source: www.gmatprepnow.com” 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 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 Brent@GMATPrepNow posted a reply to Julie opened a lemonade stand and sold lemonade in two in the Data Sufficiency forum “This question illustrates a common trap on the GMAT. For statement 2, we''re able to write the equation 52x + 58y = 492 , and in high school we learned that, if we''re given 1 equation with 2 variables, we cannot find the value of either variable. However, if we restrict the variables to ...” October 11, 2018 Brent@GMATPrepNow posted a reply to There are 5 cars to be displayed in 5 parking spaces with in the Problem Solving forum “Let R, R, R, B, Y represent the cars (by their colors) Notice that the three R''s are identical. So, the question becomes In how many different ways can we arrange the letters R, R, R, B and Y? ----------------ASIDE------------------------------ When we want to arrange a group of items in ...” October 10, 2018 Brent@GMATPrepNow posted a reply to Is x/11 an integer? in the Data Sufficiency forum “Target question: Is x/11 an integer? Statement 1: 5x/11 is an integer Let''s TEST some values There are several values of x that satisfy statement 1. Here are two: Case a: x = 11. Notice that 5x/11 = 5(11)/11 = 5, which is an integer. In this case, x/11 = 11/11 = 1. So, the answer to the ...” October 10, 2018 Brent@GMATPrepNow posted a reply to Dick and Jane each saved$3000 in 1989. In 1990 Dick save 8 in the Problem Solving forum
“Here''s the original wording: In 1990, Dick saved 8 percent more than in 1989 So, Dick''s savings in 1990 = 1.08($3000) =$3240 In 1990, Dick and Jane saved a total of $5,000. So, Jane''s savings =$5,000 - $3240 =$1760 Approximately what percent less did Jane save in 1990 than in ...”
October 10, 2018
Brent@GMATPrepNow posted a reply to Pam and Sue drove in the same car to a business meeting that in the Problem Solving forum
“Travel time = distance/speed Pam''s travel time = 120 miles/60 mph =2 hours Sue''s travel time = 120 miles/50 mph =2.4 hours Time difference = 2.4 hours - 2 hours = 0.4 hours To convert 0.4 hours to minutes, recognize that 1 hour = 60 minutes So, 0.4 hours = (0.4)(60) minutes = 24 minutes ...”
October 10, 2018
Brent@GMATPrepNow posted a reply to A group of medical interns at Bohemus Medical School want to in the Problem Solving forum
“Take the task of arranging dates and break it into stages. Let A, B, C, D and E represent the 5 girls Stage 1: Select a boy to date girl A We can choose any of the 5 boys, so we can complete stage 1 in 5 ways Stage 2: Select a boy to date girl B Since we already selected a boy in ...”
October 9, 2018
Brent@GMATPrepNow posted a reply to A school library contains 200 hardcover and 300 paperback in the Problem Solving forum
“Another approach is to use the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it (aka overlapping sets questions). Here, we have a population of books, and the two characteristics are: - ...”
October 9, 2018
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“Here''s our video on the Double Matrix Method for overlapping sets: https://www.youtube.com/watch?v=jK-tiBrrf04 Cheers, Brent”
October 9, 2018
Brent@GMATPrepNow posted a reply to If x, y, and z are positive numbers, Is z between x and y? in the Data Sufficiency forum
“Target question: Is z between x and y? Statement 1: x < 2z < y There are several sets of values of x, y and z that satisfy this condition. Here are two: Case a: x = 3, y = 10, and z = 2, in which case z is NOT between x and y Case b: x = 1, y = 10, and z = 3, in which case z IS ...”
October 9, 2018
Brent@GMATPrepNow posted a reply to If the product of X and Y is a positive number, is the sum in the Data Sufficiency forum
“IMPORTANT CONCEPTS: An ODD power preserves the sign of the base. For example, (-5)^3 = -125 and 2^5 = 32 An EVEN power always yields a positive number (as long as the base ≠ 0 For example, (-5)^4 = 625 and 2^6 = 64 Target question: Is the sum of x and y negative? Given: the ...”
October 9, 2018
Brent@GMATPrepNow posted a reply to DS: Difficulty level: 700, Source: Economist in the GMAT Math forum
“The key word here is must So, if we can find a case in which an answer choice is NOT true, then we can eliminate that answer choice. A. x is odd and y is even. x = 3 and y = 11 satisfies the condition that x/y is not an integer Since y is NOT even, we can ELIMINATE A B. x is odd and y is ...”
October 9, 2018
Brent@GMATPrepNow posted a reply to James invested $5000 in scheme A for 1 year at a simple in the Problem Solving forum “Scheme A Interest = 5% of$5,000 = $250 Scheme B 10% interest compounded semi-annually means that the interest is compounded 2 times (in 1 year) at a rate of 5% each time One option is to apply the compound interest formula, but since we''re only compounding the interest twice, it may be ...” October 9, 2018 Brent@GMATPrepNow posted a reply to A retailer buys cases of 24 shirts for$30/case and then in the Problem Solving forum
“The key information here is that the retailer sold all the shirts it purchased This is a huge hint! For example, we know that the retailer did NOT buy only 1 case of 24 shirts, because 24 shirts will not divide into packs of 5 shirts. Likewise, we know that the retailer did NOT buy 2 cases of ...”
October 8, 2018
Brent@GMATPrepNow posted a reply to If x^2-3x=10, what is the value of x? in the Data Sufficiency forum
“ Given: x² - 3x = 10 Subtract 10 from both sides to get: x² - 3x - 10 = 0 Factor: (x - 5)(x + 2) = 0 So, EITHER x = 5 OR x = -2 Target question: What is the value of x? Statement 1: x² - 4 = 0 Factor: (x + 2)(x - 2) = 0 So, EITHER x = -2 OR x = 2 When we combine this with the fact ...”
October 8, 2018
Brent@GMATPrepNow posted a reply to What is the greatest prime factor of 1+2+3+….+36? in the Problem Solving forum
“Useful formula: 1 + 2 + 3 + 4 + . . . . + n = (n)(n + 1)/2 So, 1 + 2 + 3 + …. + 36 = (36)(36 + 1)/2 = (36)(37)/2 = (18)(37) = (2)(3)(3)(17) So, the greatest prime factor is 37 Answer: E Cheers, Brent”
October 8, 2018
Brent@GMATPrepNow posted a reply to Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“In this short (3:25) video, we''ll examine the age-old question When do I use IF and when do we use WHETHER? Video link: https://www.youtube.com/watch?v=F2ZHtB088us Cheers, Brent”
October 7, 2018
Brent@GMATPrepNow posted a reply to All assets in Karina's investment portfolio are divided in the Problem Solving forum
“Let''s say Karina''s entire portfolio is worth $100 altogether. So, we want to divide this$100 into four integer amounts: w, x, y, z, where w < x < y < z, and we want to minimize the value of z In order to MINIMIZE the value of the z, we must MAXIMIZE the values of w, x, and y. Now ...”
October 7, 2018
Brent@GMATPrepNow posted a reply to Beth and Jim each received a salary increase. If Jim's in the Data Sufficiency forum
“Target question: Did Beth receive a greater dollar increase in salary than Jim? Given: Jim''s salary was increased by the same percent as Beth''s salary Statement 1: Before the increases, Jim''s salary was greater than $25,000. Since we have no information about Beth, there''s no way to ...” October 7, 2018 Brent@GMATPrepNow posted a reply to Problem solving: Difficulty level: 700, Source: Jamboree in the Problem Solving forum “Take: x² + 5|x| + 6 = 0 Subtract 6 from both sides to get: x² + 5|x| = -6 KEY CONCEPT: x² ≥ 0 and |x| ≥ 0 for all values of x In other words, x² will always be greater than or equal to 0 And |x| will always be greater than or equal to 0, which means 5|x| will always be greater than or ...” October 7, 2018 Brent@GMATPrepNow posted a reply to TRICKY! There are n teams playing in a basketball tournam in the Problem Solving forum “Good catch regor60! A few people alerted me to this error earlier in the day, but I was on the road and couldn''t respond. Man, I must have solved the question 3 or 4 times to make sure the numbers added up, BUT I never considered the impossibility of more than one team winning every game. ...” October 7, 2018 Brent@GMATPrepNow posted a reply to Is -3*x^3 <= -3? in the Data Sufficiency forum “Target question: Is (-3)(x³) ≤ -3? This is a good candidate for rephrasing the target question. Take: (-3)(x³) ≤ -3? Divide both sides by -3 to get: x³ ≥ 1 Under what circumstance will x³ be greater than or equal to 1? Well, x³ EQUALS 1 when x = 1 So, x³ will be greater than ...” October 6, 2018 Brent@GMATPrepNow posted a reply to If x + 5 > 2 and x - 3 < 7, the value of x must be bet in the Problem Solving forum “GIVEN: x + 5 > 2 Subtract 5 from both sides of the inequality to get: x > -3 Or we can write this as -3 < x GIVEN: x - 3 < 7 Add 3 to both sides of the inequality to get: x < 10 COMBINE the inequalities to get: -3 < x < 10 Answer: A Cheers, Brent” October 6, 2018 Brent@GMATPrepNow posted a reply to Each year for 4 years, a farmer increased the number of in the Problem Solving forum “Here''s another approach: First notice that, if the number of trees increases by 1/4, then the new number is 5/4 times the original number. Let x = the # of trees in the orchard at the beginning of the 4 year period. (5/4)x = # of trees after 1 year (5/4)(5/4)x = # of trees after 2 years ...” October 5, 2018 Brent@GMATPrepNow posted a reply to Health insurance Plan A requires the insured to pay$1000 or in the Problem Solving forum
“Here''s an algebraic approach: Let T = TOTAL COST Plan A: Person pays EITHER $1000 OR 0.5T, whichever is LESS Plan B: Person pays$300 plus 20% of anything over $300. In other words, the person pays$300 + 0.2(T - 300) Since Plan A has two different scenarios, we need to test both. That ...”
October 5, 2018
Brent@GMATPrepNow posted a new topic called Bite-sized video lessons from GMAT Prep Now in the GMAT Math forum
“I thought I''d start a thread featuring some of the videos from our course. This first video is one of my favorites. It covers a useful mental-math technique called Multiplying by Doubling and Halving (length 3:25) Video link: https://www.youtube.com/watch?v=D__dWwmgq2w All the best on ...”
October 5, 2018
Brent@GMATPrepNow posted a new topic called TRICKY! There are n teams playing in a basketball tournam in the Problem Solving forum
“Several teams are competing in a basketball tournament, and each team plays every other team once. Each game has exactly 1 winner and 1 loser (no ties). If 4 teams lost exactly 5 games, 5 teams won exactly 3 games, and each of the remaining teams won all of its games, what is the total number of ...”
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
Brent@GMATPrepNow posted a reply to Andrew bought pizzas for his swim team. Pepperoni pizzas in the Problem Solving forum
“This question illustrates the difference between the abstract math and real world math. From the given information, we''re able to create ONE equation: 13p + 17c = 184 In high school, we learned that, if we''re given 1 equation with 2 variables, we cannot find the value of either variable, so ...”
October 5, 2018
Brent@GMATPrepNow posted a reply to ||2-3|-|2-5||=? in the Problem Solving forum
“||2-3|-|2-5|| = ||-1|-|-3|| = |1-3|| = |-2| = 2 Answer: B Cheers, Brent”
October 5, 2018
Brent@GMATPrepNow posted a reply to What is the perimeter of quadrilateral Q? in the Data Sufficiency forum
“Target question: What is the perimeter of quadrilateral Q? If we recognize that each statement alone is not sufficient, we can jump straight to...... Statements 1 and 2 combined There are several quadrilaterals that satisfy BOTH statements. Here are two: Case a: rectangle Q has ...”
October 5, 2018
Brent@GMATPrepNow posted a reply to A car salesman earns a base salary of $1,000 per month plus in the Problem Solving forum “Let x = number of cars sold in 1 month So, his pay =$1000 + ($200)(n) If he earned$2,200 in February, how many cars does he have to sell in March in order to double his February earnings? If we double $2,200, we get$4,400 We need: $1,000 + ($200)(n) = $4400 Subtract$1,000 from both sides ...”
October 4, 2018
Brent@GMATPrepNow posted a reply to If p and q are prime numbers, is pq+1 an odd number? in the Data Sufficiency forum
“Be careful, deloitte247 You haven''t used the information about p and q being prime numbers. Cheers, Brent”
October 4, 2018
Brent@GMATPrepNow posted a reply to In the figure above, A is the center of the circle, DF is 5, in the Problem Solving forum
“As you can see from my solution above, this question is a time-killer (even if you answer it correctly!!) So, if you''re running short on time, you can reduce the correct answers to two options, and make your best guess How so? IMPORTANT: the diagrams in GMAT problem solving questions are DRAWN ...”
October 4, 2018
Brent@GMATPrepNow posted a reply to In the figure above, A is the center of the circle, DF is 5, in the Problem Solving forum
“As you can see from my solution above, this question is a time-killer (even if you answer it correctly) So, if you''re running short on time, you can reduce the correct answers to two options, and make your best guess How so? IMPORTANT: the diagrams in GMAT problem solving questions are DRAWN TO ...”
October 4, 2018
Brent@GMATPrepNow posted a reply to In the figure above, A is the center of the circle, DF is 5, in the Problem Solving forum
“Let x = the length of AF https://i.imgur.com/pT36mTR.png This means AD = x + 5 = radius of the circle. This is convenient, because AE is also a radius of the circle. So, AE must have length x + 5 https://i.imgur.com/aLGqKow.png At this point, we can focus on the RIGHT TRIANGLE below: ...”
October 4, 2018
Brent@GMATPrepNow posted a reply to If p and q are prime numbers, is pq+1 an odd number? in the Data Sufficiency forum
“ Given: p and q are prime numbers Target question: Is pq + 1 an odd number? This is a good candidate for rephrasing the target question. In order for pq + 1 to be odd, we need pq to be EVEN So, we COULD rephrase our target question as Is pq an even number?, but we can do even better than ...”
October 4, 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
Brent@GMATPrepNow posted a reply to A political candidate collected $1,749 from a fund raising in the Problem Solving forum “In order to MAXIMIZE the number of contributors, we must MINIMIZE the amount that each supporter contributes. So, let''s say that each supporter contributes exactly$50 (which is the minimum about that each supporter contributes) $50 divides into$1,749 a total of 34 times (with $49 left over). ...” October 4, 2018 Brent@GMATPrepNow posted a reply to If x^2 + 3x + 3 = 5x + 6 then x equals in the Problem Solving forum “nonplus2''s approach is the as mine, but a reasonably fast alternative approach is to test the answer choices . Answer choice A suggests that one possible solution is x = -1 So, plug x = -1 into the equation to get: (-1)² + 3(-1) + 3 = 5(-1) + 6 Simplify to get: 1 = 1. Perfect!!! So, x = -1 ...” October 4, 2018 Brent@GMATPrepNow posted a reply to A thin piece of wire 40 meters long is cut into two pieces. in the Problem Solving forum “One approach is to plug in a value for r and see what the output should be. Let''s say r = 0. That is, the radius of the circle = 0 This means, we use the entire 40-meter length of wire to create the square. So, the 4 sides of this square will have length 10, which means the area = 100 So, ...” October 4, 2018 Brent@GMATPrepNow posted a reply to The price of a phone call consists of a standard connection in the Problem Solving forum “A 10-minute call costs$2.90 and a 16-minute call costs $4.40$4.40 - $2.90 =$1.50, and 16 minutes - 10 minutes = 6 minutes So, the extra $1.50 paid for extra 6 minutes of calling So,$0.75 would pay for 3 minutes of calling How much does a 13-minute call cost? A 10-minute call costs ...”
October 4, 2018
Brent@GMATPrepNow posted a reply to How many ounces of water must be added to 10 ounces of 3 % in the Problem Solving forum
“The original solution contains 10 ounces 3% of that is alcohol 3% of 10 = 0.3 So, the original solution contains 0.3 ounces of alcohol Let x = the amount of water (in ounces) that must be added So, the volume of the RESULTING solution = 10 + x ounces IMPORTANT: Since we''re adding water ...”
October 3, 2018
Brent@GMATPrepNow posted a reply to Ken has a group of coins worth $6.70. He has four times as m in the Problem Solving forum “Let x = the NUMBER of dimes So, 4x = the NUMBER of nickels And 4x - 20 = the NUMBER of quarters One dime is worth$0.1, so 0.10x = the total VALUE of the dimes (in dollars) Likewise, (0.05)(4x) = the total VALUE of the nickels (in dollars) And (0.25)(4x - 20) = the total VALUE of the ...”
October 3, 2018
Brent@GMATPrepNow posted a reply to Goku and Vegeta are waiting in a line, are there more than 1 in the Data Sufficiency forum
“Target question: Are there more than 10 people waiting in the line? Head straight to... Statements 1 and 2 combined There are several scenarios that satisfy BOTH statements. Here are two: Case a: BACK A, B, C, D, Vegeta, Picollo, Goku, E, F, G, H FRONT. In this case, the answer to the ...”
October 3, 2018
Brent@GMATPrepNow posted a reply to Vivian drives to her sister's house and back. She takes the in the Problem Solving forum
“One approach is to assign a "nice" value (one that works well with 50 mph and 70 mph) to the distance her sister''s house. So, let''s say the distance is 350 miles Average speed = (total distance traveled)/(total travel time) TOTAL distance = 350 miles + 350 miles = 700 miles ...”
October 3, 2018
Brent@GMATPrepNow posted a reply to Tom’s Mom is five times as old as him. In 6 years, Tom’ in the Problem Solving forum
“Tom’s Mom is five times as old as him. Let T = Tom''s PRESENT age So, 5T = Mom''s PRESENT age This also means: Let T + 6= Tom''s age IN 6 YEARS and 5T + 6 = Mom''s age IN 6 YEARS In 6 years, Tom’s Mom will be three times as old as Tom. In other words: (Mom''s age IN 6 YEARS) = ...”
October 3, 2018
Brent@GMATPrepNow posted a reply to A “descending number” is a three-digit number, such that in the Problem Solving forum
“Let''s use some counting methods to solve this. P(selected number is "descending") = total # of descending numbers/total # of 3-digit numbers total # of 3-digit numbers 3-digit numbers go from 100 to 999 inclusive A nice rule says: the number of integers from x to y inclusive ...”
October 3, 2018
Brent@GMATPrepNow posted a reply to Challenge question: If y < 0 < x, is x/y > -1? in the Data Sufficiency forum
“I checked the link you provided, Fabio. For me, the response from the test-makers that sticks out the most is this: "it is highly unlikely that you would come across a question with independently sufficient statements that contradict each other" I think the person answering the ...”
October 2, 2018
Brent@GMATPrepNow posted a reply to Challenge question: If y < 0 < x, is x/y > -1? in the Data Sufficiency forum
“My apologies. I posted my question without noticing its FATAL FLAW. KEY CONCEPT: On the GMAT, the two statements in a Data Sufficiency question will never contradict each other (for more on this, see the video below) Let''s examine the main issue. Statement 1: x + y > 0 Okay, so x + ...”
October 2, 2018
Brent@GMATPrepNow posted a reply to During a two-week period, the price of an ounce of silver in the Problem Solving forum
“Another approach is to test a "nice" value x A great value would be $80 (since we get$100 after we increase $80 by 25%) So, x =$80 In other words, the price of silver was $80 per ounce at the beginning of the two-week period. During a two-week period, the price of an ounce of ...” October 2, 2018 Brent@GMATPrepNow posted a new topic called Challenge question: If y < 0 < x, is x/y > -1? in the Data Sufficiency forum “If y < 0 < x, is x/y > -1? (1) x + y > 0 (2) 3x < -2y Answer: D Difficulty level: 600 - 650 Source: www.gmatprepnow.com” October 2, 2018 Brent@GMATPrepNow posted a reply to For all values of x and y , let x&y be defined by x& in the Problem Solving forum “Nice question! GIVEN: x&y = xy − x + 1 So, take the equation: (a − 2)&a = a&(a + 1) Apply rules to get the equation: (a - 2)(a) - (a - 2) + 1 = (a)(a + 1) - a + 1 Expand: a² - 2a - a + 2 + 1 = a² + a - a + 1 Simplify: a² - 3a + 3 = a² + 1 Subtract a² from both sides ...” October 2, 2018 Brent@GMATPrepNow posted a reply to If 3 different numbers are selected from the first 8 prime n in the Problem Solving forum “The first 8 prime numbers are: {2, 3, 5, 7, 11, 13, 17, 19} Notice that only one prime number is EVEN, and the remaining seven numbers are ODD. Also notice that the sum of 3 numbers will be EVEN only if one of the three selected numbers is 2 So, the question is really asking "What is the ...” October 2, 2018 Brent@GMATPrepNow posted a reply to The symbol Ω represents one of the following operations: ad in the Data Sufficiency forum “Target question: What is the value of 1 Ω 1? Given: Ω represents one of the following operations: addition, subtraction, multiplication or division. Statement 1: 2 Ω 2 = 4 2 - 2 = 0, so Ω CANNOT represent subtraction. 2 ÷ 2 = 1, so Ω CANNOT represent division. 2 + 2 = 4, so ...” October 2, 2018 Brent@GMATPrepNow posted a reply to On a 20 mile course, Pat bicycled at an average rate of 30 in the Problem Solving forum “Let''s start with a WORD EQUATION (Distance traveled at 30 mph) + (Distance traveled at 8 mph) = 20 miles Distance = (rate)(time) Let t = the time (in hours) Pat spent running at 8 mph Aside: 12 minutes = 1/5 hours So, we get: (30 miles per hour)(1/5 hours) + (8 miles per hour)(t ...” October 2, 2018 Brent@GMATPrepNow posted a reply to The greatest common factor of 16 and the positive integer n in the Problem Solving forum “Now, we can use ELIMINATION to find the correct answer. Goal: Find GCF of 210 and n. 210 = (2)(3)(5)(7) The greatest common factor of 16 and the positive integer n is 4 16 = (2)(2)(2)(2) 4 = (2)(2) So, we know for certain that the PRIME FACTORIZATION of n has TWO 2''s (and no more than ...” October 2, 2018 Brent@GMATPrepNow posted a reply to Jan lives x floors above the ground floor of a highrise in the Problem Solving forum “Let''s first convert 7 minutes to SECONDS in order to have uniform units of measurement. 7 minutes = 420 seconds Let''s start with a word equation Jan''s travel time (in seconds) WALKING down = Jan''s travel time (in seconds) via ELEVATOR + 420 seconds It takes her 30 seconds per floor to ...” October 1, 2018 Brent@GMATPrepNow posted a reply to Five letters A, P, P, L and E are listed in a row. How many in the Problem Solving forum “Here''s an approach that doesn''t require us to subtract the bad arrangements. Take the task of arranging the 5 letters and break it into stages. Stage 1: Arrange the letters A, L, E in a row We can arrange n unique objects in n! ways. So, we can arrange the 3 letters in 3! ways (= 6 ...” October 1, 2018 Brent@GMATPrepNow posted a reply to Jevan must paint 3 rooms in a house. Room A can be painted in the Problem Solving forum “Take the task of painting the 3 rooms and break it into stages. Stage 1: Select a color for Room A Room A can be painted orange, red or green So, we can complete stage 1 in 3 ways Stage 2: Select a color for Room B Room B can be painted orange, white or red. So we can complete this ...” October 1, 2018 Brent@GMATPrepNow posted a reply to Improve My Overall Score in the Last Leg of Preparation? in the GMAT Strategy forum “The resource labeled "OG2018" has questions from the 2018 OG See: https://www.beatthegmat.com/mba/official-guide-2018-library Cheers, Brent” October 1, 2018 Brent@GMATPrepNow posted a reply to Improve My Overall Score in the Last Leg of Preparation? in the GMAT Strategy forum “Look no further<i class="em em-grinning"></i> : https://www.beatthegmat.com/official-guide-question-library-t296755.html Cheers, Brent” October 1, 2018 Brent@GMATPrepNow posted a reply to If m and n are integers, is mn an odd integer? in the Data Sufficiency forum “Some important rules: #1. ODD +/- ODD = EVEN #2. ODD +/- EVEN = ODD #3. EVEN +/- EVEN = EVEN #4. (ODD)(ODD) = ODD #5. (ODD)(EVEN) = EVEN #6. (EVEN)(EVEN) = EVEN Target question: Is mn an odd integer? Given: m and n are integers Statement 1: m(n+1) is even Let''s test some ...” October 1, 2018 Brent@GMATPrepNow posted a reply to If n is an integer, is n even? in the Data Sufficiency forum “Some important rules: 1. ODD +/- ODD = EVEN 2. EVEN +/- ODD = ODD 3. EVEN +/- EVEN = EVEN 4. (ODD)(ODD) = ODD 5. (ODD)(EVEN) = EVEN 6. (EVEN)(EVEN) = EVEN Target question: Is integer n EVEN? Statement 1: n² - 1 is an odd integer n² - 1 = (n + 1)(n - 1) So, statement 1 is ...” October 1, 2018 Brent@GMATPrepNow posted a reply to When positive integer n is divided by 13, the remainder is 2 in the Problem Solving forum “When it comes to remainders, we have a nice rule that says: If N divided by D leaves remainder R, then the possible values of N are R, R+D, R+2D, R+3D,. . . etc. For example, if k divided by 5 leaves a remainder of 1, then the possible values of k are: 1, 1+5, 1+(2)(5), 1+(3)(5), ...” September 30, 2018 Brent@GMATPrepNow posted a reply to A marketing firm determined that, of 200 households surveyed in the Problem Solving forum “We can also solve this question using the Double Matrix Method. Here, we have a population of 200 households , and the two characteristics are: - using or not using Brand A soap - using or not using Brand B soap So, we can set up our matrix as follows (where "~" represents ...” September 30, 2018 Brent@GMATPrepNow posted a reply to Lindsay can paint 1/x of a certain room in 20 minutes. What in the Problem Solving forum “Given: Lindsay can paint 1/x of a certain room in 20 minutes So, in 1 HOUR, Lindsay can paint 3/x of the room Given: Lindsay and Joseph can paint the room in 1 HOUR. During that one hour, Lindsay can paint 3/x of the room. So, during that 1 HOUR, Joseph must paint the rest (whatever Lindsay ...” September 30, 2018 Brent@GMATPrepNow posted a reply to PS : In a certain clothing store in the Problem Solving forum “Let C = price of one pair of the CHEAPEST socks So, 2C - 1 = price of one pair of the MOST EXPENSIVE socks A customer notices that for exactly$18, she can buy three fewer pairs of the most expensive socks than the cheapest socks. As a word equation, we can write: (# of pairs of EXPENSIVE ...”
September 30, 2018
Brent@GMATPrepNow posted a reply to If x and y are positive integers, is x/y < (x+5)/(y+5)? in the Data Sufficiency forum
“ Given: x and y are positive integers Target question: Is x/y < (x+5)/(y+5)? This is a good candidate for rephrasing the target question. Since y is POSITIVE, we can safely take the inequality x/y < (x+5)/(y+5) and multiply both sides by y. When we do this, we get: x < ...”
September 30, 2018