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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 ## A group of medical interns at Bohemus Medical School want to ##### This topic has 4 expert replies and 0 member replies ### Top Member ## A group of medical interns at Bohemus Medical School want to ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult A group of medical interns at Bohemus Medical School want to go on dates. There are 5 girls and 5 guys. Assuming girls go on dates with guys, how many possible ways can these 10 medical interns date each other? (A) 10 (B) 25 (C) 60 (D) 90 (E) 120 ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 14823 messages Followed by: 1850 members Upvotes: 13060 GMAT Score: 790 subh2273 wrote: A group of medical interns at Bohemus Medical School want to go on dates. There are 5 girls and 5 guys. Assuming girls go on dates with guys, how many possible ways can these 10 medical interns date each other? (A) 10 (B) 25 (C) 60 (D) 90 (E) 120 In other words: How many ways can 5 girls and 5 guys be divided into pairs, if each pair must consist of one girl and one guy? Number of options for the first girl = 5. (Any of the 5 guys.) Number of options for the second girl = 4. (Any of the 4 remaining guys). Number of options for the third girl = 3. (Any of the 3 remaining guys.) Number of options for the fourth girl = 2. (Either of the 2 remaining guys.) Number of options for the fifth girl = 1. (Only one guy left.) To combine the options above, we multiply: 5*4*3*2*1 = 120. The correct answer is E. _________________ 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 08 Dec 2008 Posted: 12253 messages Followed by: 1239 members Upvotes: 5254 GMAT Score: 770 subh2273 wrote: A group of medical interns at Bohemus Medical School want to go on dates. There are 5 girls and 5 guys. Assuming girls go on dates with guys, how many possible ways can these 10 medical interns date each other? (A) 10 (B) 25 (C) 60 (D) 90 (E) 120 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 stage 1, there are 4 boys remaining to choose from. So we can complete stage 2 in 4 ways Stage 3: Select a boy to date girl C There are 3 boys remaining to choose from. So we can complete stage 3 in 3 ways Stage 4: Select a boy to date girl D 2 boys remaining. So we can complete stage 4 in 2 ways Stage 5: Select a boy to date girl E There is 1 boy remaining to be seated, so we can complete stage 5 in 1 way By the Fundamental Counting Principle (FCP), we can complete all 5 stages (and thus arrange all dates) in (5)(4)(3)(2)(1) ways (= 120 ways) Answer: E Note: the FCP can be used to solve the MAJORITY of counting questions on the GMAT. For more information about the FCP, watch our free video: http://www.gmatprepnow.com/module/gmat-counting/video/775 You can also watch a demonstration of the FCP in action: https://www.gmatprepnow.com/module/gmat-counting/video/776 Then you can try solving the following questions: EASY - https://www.beatthegmat.com/what-should-be-the-answer-t267256.html - https://www.beatthegmat.com/counting-problem-company-recruitment-t244302.html - https://www.beatthegmat.com/picking-a-5-digit-code-with-an-odd-middle-digit-t273110.html - https://www.beatthegmat.com/permutation-combination-simple-one-t257412.html - https://www.beatthegmat.com/simple-one-t270061.html MEDIUM - https://www.beatthegmat.com/combinatorics-solution-explanation-t273194.html - https://www.beatthegmat.com/arabian-horses-good-one-t150703.html - https://www.beatthegmat.com/sub-sets-probability-t273337.html - https://www.beatthegmat.com/combinatorics-problem-t273180.html - https://www.beatthegmat.com/digits-numbers-t270127.html - https://www.beatthegmat.com/doubt-on-separator-method-t271047.html - https://www.beatthegmat.com/combinatorics-problem-t267079.html DIFFICULT - https://www.beatthegmat.com/wonderful-p-c-ques-t271001.html - https://www.beatthegmat.com/permutation-and-combination-t273915.html - https://www.beatthegmat.com/permutation-t122873.html - https://www.beatthegmat.com/no-two-ladies-sit-together-t275661.html - https://www.beatthegmat.com/combinations-t123249.html Cheers, Brent _________________ Brent Hanneson â€“ Creator of GMATPrepNow.com Use our video course along with Sign up for our free Question of the Day emails And check out all of our free resources GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMATâ€™s FREE 60-Day Study Guide and reach your target score in 2 months! ### GMAT/MBA Expert GMAT Instructor Joined 09 Oct 2010 Posted: 729 messages Followed by: 26 members Upvotes: 59 subh2273 wrote: A group of medical interns at Bohemus Medical School want to go on dates. There are 5 girls and 5 guys. Assuming girls go on dates with guys, how many possible ways can these 10 medical interns date each other? $$(A) 10 \,\,\,\,\,\,\,\,\,\,\, (B) 25 \,\,\,\,\,\,\,\,\,\,\, (C) 60 \,\,\,\,\,\,\,\,\,\,\, (D) 90 \,\,\,\,\,\,\,\,\,\,\, (E) 120$$ $?\,\,\,\,:\,\,\,\,\# \,\,\,{\text{guy - girl}}\,\,{\text{pairs}}$ Imagine girls in a row (say) in alphabetical order. FOCUS: number of ways to put 5 guys in a row (parallel to the first row, each guy facing one girl - this is a pair!) $?\, = \,{P_{\,5}}\,\, = 5! = 120$ This solution follows the notations and rationale taught in the GMATH method. Regards, Fabio. _________________ Fabio Skilnik :: https://GMATH.net (Math for the GMAT) Testimonials :: https://GMATH.net/testimonials.html Course release PROMO : finish our test drive till 31/Oct with (at least) 60 correct answers out of 92 (12-questions Mock included) to gain a 60% discount! ### GMAT/MBA Expert GMAT Instructor Joined 25 Apr 2015 Posted: 1651 messages Followed by: 14 members Upvotes: 43 subh2273 wrote: A group of medical interns at Bohemus Medical School want to go on dates. There are 5 girls and 5 guys. Assuming girls go on dates with guys, how many possible ways can these 10 medical interns date each other? (A) 10 (B) 25 (C) 60 (D) 90 (E) 120 The first girl has 5 choices of guys, the second girl has 4 choices of guys (after a guy is picked by the first girl), the third girl has 3 choices of guys (after a guy is picked by the second girl), and so on. So the number of ways these 10 interns can date each other is 5 x 4 x 3 x 2 x 1 = 120. Answer: E _________________ Scott Woodbury-Stewart Founder and CEO • 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 • Free Veritas GMAT Class Experience Lesson 1 Live Free 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 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Award-winning private GMAT tutoring Register now and save up to$200

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