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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 ## Angela’s grade was in the 90th percentile out of 80 grades tagged by: swerve ##### This topic has 4 expert replies and 0 member replies ### Top Member ## Angela’s grade was in the 90th percentile out of 80 grades ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult Angela’s grade was in the 90th percentile out of 80 grades in her class. In another class of 100 students there were 19 grades higher than Angela’s. If nobody had Angela’s grade, then Angela was what percentile of the two classes combined? A. 72 B. 80 C. 81 D. 85 E. 92 The OA is D. Source: GMAT Prep ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15186 messages Followed by: 1860 members Upvotes: 13060 GMAT Score: 790 swerve wrote: Angela’s grade was in the 90th percentile out of 80 grades in her class. In another class of 100 students there were 19 grades higher than Angela’s. If nobody had Angela’s grade, then Angela was what percentile of the two classes combined? A. 72 B. 80 C. 81 D. 85 E. 92 Percentile means the percentage below: (total below)/(total grades) * 100. Angela's 80-student class: Since Angela's grade was in the 90th percentile, 90% of the grades were below Angela's: (90/100)(80) = 72. 100-student class: Since 19 grades were higher than Angela's, the remaining 81 grades were below Angela's. Thus, out of all 180 grades, the total number below Angela's = 72+81 = 153. Resulting percentile: (total below)/(total grades) * 100 = 153/180 *100 = 85%. The correct answer is D. _________________ Mitch Hunt Private Tutor for the GMAT and GRE GMATGuruNY@gmail.com If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon. Available for tutoring in NYC and long-distance. For more information, please email me at GMATGuruNY@gmail.com. Student Review #1 Student Review #2 Student Review #3 Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now. ### GMAT/MBA Expert GMAT Instructor Joined 09 Oct 2010 Posted: 1429 messages Followed by: 31 members Upvotes: 59 swerve wrote: Angela’s grade was in the 90th percentile out of 80 grades in her class. In another class of 100 students there were 19 grades higher than Angela’s. If nobody had Angela’s grade, then Angela was what percentile of the two classes combined? A. 72 B. 80 C. 81 D. 85 E. 92 Source: GMAT Prep The solution previously presented here was very similar to Mitch´s (above), therefore I have decided to change it. The approximation presented is validated a posteriori, because there are no alternative choices "near" the correct one! (If you prefer an exact solution, choose Mitch´s or the one I posted right after this one.) $?\,\,\,\,:\,\,\,{\text{Angela}}\,\,{\text{percentile}}$ $\left\{ \begin{gathered} \,80\,\,{\text{people}}\,\,\,:\,\,\,90\% \,\,{\text{below}} \hfill \\ \,10\boxed1\,\,\,{\text{people}}\,\,\,:\,\,\,\, \cong 80\% \,\,{\text{below}}\,\,\, \hfill \\ \end{gathered} \right.\,\,\,\,\,\,\,\,\,\,\, \cong \,\,\,\,\,\,\,\left\{ \begin{gathered} \,\,4\,\,{\text{people}}\,\,\,:\,\,\,90\% \,\,{\text{below}} \hfill \\ \,\,5\,\,\,{\text{people}}\,\,\,:\,\,\,80\% \,\,{\text{below}}\,\, \hfill \\ \end{gathered} \right.$ $\boxed1\,\,\,:\,\,\,{\text{if}}\,\,{\text{Angela}}\,\,{\text{there!}}$ $?\,\,\, \cong \,\,\,\frac{{4 \cdot 90\% + 5 \cdot 80\% }}{9}\,\,\, \cong \,\,\,\frac{{4 \cdot 90\% + 5 \cdot 81\% }}{9}\,\,\, = \,\,\,4 \cdot 10\% + 5 \cdot 9\% \,\,\, = \,\,\,85\%$ 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 Last edited by fskilnik@GMATH on Wed Oct 10, 2018 11:35 am; edited 1 time in total ### GMAT/MBA Expert GMAT Instructor Joined 09 Oct 2010 Posted: 1429 messages Followed by: 31 members Upvotes: 59 swerve wrote: Angela’s grade was in the 90th percentile out of 80 grades in her class. In another class of 100 students there were 19 grades higher than Angela’s. If nobody had Angela’s grade, then Angela was what percentile of the two classes combined? A. 72 B. 80 C. 81 D. 85 E. 92 Source: GMAT Prep $?\,\, = \,\,\frac{{\# \,\,{\text{below}}\,\,{\text{Angela}}}}{{\# \,\,{\text{total}}}}\, \cdot \,\,100\,\,\,\left( \% \right)$ Alternate approach: Angela was in the "10th best grades" (but not better) in her class (80 students), hence (she is "number 8" and) there are 7 grades above her. From the question stem, there are 7+19 = 26 grades above her in 180 grades, therefore 180-26-1 = 153 below her. $? = \frac{{153}}{{180}}\, \cdot \,\,100 = \,\underleftrightarrow {\frac{{\left( {90 + 63} \right)}}{9} \cdot \frac{{10}}{2}} = \,\,17 \cdot 5 = 85\,\,\,\left( \% \right)$ 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 Elite Legendary Member Joined 23 Jun 2013 Posted: 10106 messages Followed by: 494 members Upvotes: 2867 GMAT Score: 800 Hi swerve, We're told that Angela’s grade was in the 90th percentile out of 80 grades in her class and in another class of 100 students there were 19 grades higher than Angela’s grade. We're asked - if nobody had the same grade as Angela’s grade, what percentile was Angela in the two classes combined. This question can be solved in a couple of different ways; based on the 'spread' of the answer choices, you can actually answer this question with some logic and just a little math. We know that Angela is the 90th percentile in the first class. With 100 students in the second class, and 19 of them 'ahead' of Angela, this means that she's the 100 - 19 = 81st percentile in that class. Thus, when you combine those two classes, Angela will be somewhere in the 81st to 90th percentile (but not 81st nor 90th). There's only one answer that fits that range... Final Answer: D GMAT assassins aren't born, they're made, Rich • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE 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 • Award-winning private GMAT tutoring Register now and save up to$200

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