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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 ## Total students ##### This topic has 2 expert replies and 2 member replies ## Total students Of the final grades received by the students in a certain math course, 1/5 are A's, 1/4 are B's, 1/2 are C's,and the remaining 10 grades are D's. What is the number of students in the course? (A) 80 (B) 110 (C) 160 (D) 200 (E) 400 plz suggest time saving way to solve this. _________________ Thanks and regards, Saurabh Mahajan I can understand you not winning,but i will not forgive you for not trying. Legendary Member Joined 28 Jul 2008 Posted: 2326 messages Followed by: 2 members Upvotes: 173 Target GMAT Score: 740 GMAT Score: 710 IMO back solving will be a killer when compared to Algebraic way..Better I shall stick to Algebraic way : X/5 + X/4 +X/2 + 10 = X solving for X ; X = 200 Senior | Next Rank: 100 Posts Joined 05 Aug 2010 Posted: 34 messages gmatmachoman wrote: IMO back solving will be a killer when compared to Algebraic way..Better I shall stick to Algebraic way : X/5 + X/4 +X/2 + 10 = X solving for X ; X = 200 Thank you very much............ ### GMAT/MBA Expert GMAT Instructor Joined 09 Apr 2015 Posted: 1461 messages Followed by: 18 members Upvotes: 39 saurabhmahajan wrote: Of the final grades received by the students in a certain math course, 1/5 are A's, 1/4 are B's, 1/2 are C's,and the remaining 10 grades are D's. What is the number of students in the course? (A) 80 (B) 110 (C) 160 (D) 200 (E) 400 We can let T = Total number of students in the math course and create the equation: 1/5(T) + 1/4(T) + 1/2(T) + 10 = T We can multiply the entire equation by 20 to cancel out the denominators of the fractions, and we have: 4T + 5T + 10T + 200 = 20T 19T + 200 = 20T 200 = T Alternate Solution: We can account for (20% + 25% + 50%) = 95% of the students for grades A through C, inclusive. This leaves 5% of the students that received a D, and this equates to 10 students. We can set up a simple proportion, where x = the total number of students in the course: 5/10 = 100/x 5x = 1000 x = 200 Answer: D _________________ Jeffrey Miller Head of GMAT Instruction ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10109 messages Followed by: 494 members Upvotes: 2867 GMAT Score: 800 Hi All, We're given data on the "breakdown" of grades in a course: 1/5 are A's, 1/4 are B's, 1/2 are C's, and the remaining 10 grades are D's. We're asked for the total number of students in the course. This question can also be solved by TESTing THE ANSWERS. To start, we need a number that can be evenly divided into 1/5s and 1/4s, so Answer B can be eliminated immediately. Let's TEST Answer C: 160 students Total = 160 1/5 are A's = 32 1/4 are B's = 40 1/2 are C's = 80 Sub-total = 152, which leaves 8 students with D's. This is TOO LOW (there are supposed to be 10 students with D's). Thus we need MORE total students. Eliminate Answers A, B and C. Since 8 is relatively close to 10, we probably don't need that many more students, so let's TEST D next.... Answer D: 200 students Total = 200 1/5 are A's = 40 1/4 are B's = 50 1/2 are C's = 100 Sub-total = 190, leaving 10 for D's. This is a MATCH for what we were told, so this MUST be the answer. Final Answer: D GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • Magoosh Study with Magoosh GMAT prep Available with Beat the GMAT members only code • 5 Day FREE Trial Study Smarter, Not Harder Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • 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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