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100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote ## If a certain concrete mixture contains gravel, water, and tagged by: AAPL ##### This topic has 2 expert replies and 1 member reply ### Top Member ## If a certain concrete mixture contains gravel, water, and ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult Princeton Review If a certain concrete mixture contains gravel, water, and sand in a 1 to 3 to 5 ratio by weight, how many pounds of gravel would be needed to produce 72 pounds the mixture? A. 72 B. 40 C. 24 D. 9 E. 8 OA E ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10197 messages Followed by: 495 members Upvotes: 2867 GMAT Score: 800 Top Reply Hi All, We're told that a certain concrete mixture contains gravel, water, and sand in a ratio of 1 to 3 to 5 by weight. We're asked for the number of pounds of gravel that would be needed to produce 72 pounds of the mixture. This math behind this question can be approached in a number of different ways (depending on how you want to work through your calculations). To start, a ratio of 1:3:5 means that for every 1 pound of gravel, we'll need 3 pounds of water and 5 pounds of sand. In essence, for every 1+3+5 = 9 pounds of this mixture, 1 pound of it will be gravel. With 72 total pounds, we have 72/9 = 8 'sets' of the 1:3:5 mixture described), so we would have 8(1) = 8 pounds of gravel, 8(3) = 24 pounds of water and 8(5) = 40 pounds of sand. You'll notice that all 3 of those numbers are in the answer choices; we're asked for the number of pounds of GRAVEL though... Final Answer: E GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com ### Top Member Legendary Member Joined 29 Oct 2017 Posted: 936 messages Followed by: 4 members We can solve this question as follows, 1X + 3X + 5X = 72 9X = 72 X=8. Hence, E is the correct answer. ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 2653 messages Followed by: 18 members Upvotes: 43 AAPL wrote: Princeton Review If a certain concrete mixture contains gravel, water, and sand in a 1 to 3 to 5 ratio by weight, how many pounds of gravel would be needed to produce 72 pounds the mixture? A. 72 B. 40 C. 24 D. 9 E. 8 We can create the ratio: Gravel : water : sand = x : 3x : 5x We can create the equation: x + 3x + 5x = 72 9x = 72 x = 8 So the number of pounds of gravel is 8. Answer: E _________________ Scott Woodbury-Stewart Founder and CEO scott@targettestprep.com See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews • Free Veritas GMAT Class Experience Lesson 1 Live Free Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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