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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 ## In a certain math department, students are required to tagged by: AAPL ##### This topic has 3 expert replies and 0 member replies ### Top Member ## In a certain math department, students are required to ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult Veritas Prep In a certain math department, students are required to enroll in either Calculus or Trigonometry, each of which is offered in beginner and advanced courses. The number of students enrolled in Trigonometry is 50% greater than the number of students enrolled in Calculus, and 60% of Calculus students are enrolled in the beginner course. If 4/5 of students are in the beginner courses, and one student is selected at random, what is the probability that an advanced Trigonometry student is selected? A. 4% B. 16% C. 20% D. 24% E. 40% OA A. ### GMAT/MBA Expert GMAT Instructor Joined 09 Oct 2010 Posted: 1449 messages Followed by: 32 members Upvotes: 59 AAPL wrote: Veritas Prep In a certain math department, students are required to enroll in either Calculus or Trigonometry BUT NOT BOTH, each of which is offered in beginner and advanced courses. The number of students enrolled in Trigonometry is 50% greater than the number of students enrolled in Calculus, and 60% of Calculus students are enrolled in the beginner course. If 4/5 of students are in the beginner courses, and one student is selected at random, what is the probability that an advanced Trigonometry student is selected? A. 4% B. 16% C. 20% D. 24% E. 40% $$? = {{{\rm{Trig}}\,\, \cap \,\,{\rm{Adv}}} \over {{\rm{Total}}}}$$ Good mix of the k technique with the grid (=double matrix, table, you-name-it)! $$?\,\,\, = \,\,\,\frac{k}{{25k}}\,\,\, = \,\,\,\frac{{1 \cdot \boxed4}}{{25 \cdot \boxed4}}\,\,\, = \,\,\,4\%$$ This solution follows the notations and rationale taught in the GMATH method. Regards, Fabio. _________________ Fabio Skilnik :: GMATH method creator ( Math for the GMAT) English-speakers :: https://www.gmath.net Portuguese-speakers :: https://www.gmath.com.br ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 2456 messages Followed by: 18 members Upvotes: 43 AAPL wrote: Veritas Prep In a certain math department, students are required to enroll in either Calculus or Trigonometry, each of which is offered in beginner and advanced courses. The number of students enrolled in Trigonometry is 50% greater than the number of students enrolled in Calculus, and 60% of Calculus students are enrolled in the beginner course. If 4/5 of students are in the beginner courses, and one student is selected at random, what is the probability that an advanced Trigonometry student is selected? A. 4% B. 16% C. 20% D. 24% E. 40% We can assume 60 students are enrolled in Trigonometry and thus 60/1.5 = 40 students are enrolled in Calculus. Furthermore, 0.6 x 40 = 24 students are enrolled in beginner Calculus and hence 16 students are enrolled in advanced Calculus. Since there are a total of 60 + 40 = 100 students, 4/5 x 100 = 80 students are in the beginner courses. Since 24 students are enrolled in beginner Calculus, 80 - 24 = 56 students are enrolled in beginner Trigonometry. That means 60 - 56 = 4 students are enrolled in advanced Trigonometry. So the probability of selecting such a student at random is 4/100 = 4%. Answer: A _________________ 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 ### GMAT/MBA Expert Elite Legendary Member Joined 23 Jun 2013 Posted: 10133 messages Followed by: 494 members Upvotes: 2867 GMAT Score: 800 Hi All, This question can be solved by TESTing VALUES and taking the proper notes. We're told that there are two classes (Calculus and Trigonometry) and each is offered in beginner and advanced courses - and that each student is enrolled in just one course. The number of students enrolled in Trigonometry is 50% greater than the number of students enrolled in Calculus.... IF.... there are 100 total students Trigonometry = 60 students Calculus = 40 students ....and 60% of Calculus students are enrolled in the beginner course.... Calculus = 40 total students -Beginner = 60% of 40 = 24 students -Advanced = 40 - 24 = 16 students ... and 4/5 of students are in the beginner courses.... 4/5 of 100 = 80 students in beginner courses -Beginning Calculus = 24 students -Beginning Trigonometry = 80 - 24 = 56 students Since there are 60 total Trigonometry students, and 56 of them are in the beginner course, 60 - 56 = 4 students in the advanced Trigonometry course We're asked for the probability that an advanced Trigonometry student is selected? That would be 4/100 = 4% Final Answer: A GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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