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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 ## Working together, Machine A and Machine B can produce a tagged by: AAPL ##### This topic has 2 expert replies and 0 member replies ### Top Member ## Working together, Machine A and Machine B can produce a ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult Magoosh Working together, Machine A and Machine B can produce a total of 200 widgets in 4 hours. How many hours would it take Machine A, working alone, to produce 200 widgets? 1) Working alone, Machine B takes 5 hours to produce 50 widgets. 2) Machine A can produce 4 widgets in the same amount of time it takes Machine B to produce 1 widget. OA D. ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 14937 messages Followed by: 1855 members Upvotes: 13060 GMAT Score: 790 AAPL wrote: Magoosh Working together, Machine A and Machine B can produce a total of 200 widgets in 4 hours. How many hours would it take Machine A, working alone, to produce 200 widgets? 1) Working alone, Machine B takes 5 hours to produce 50 widgets. 2) Machine A can produce 4 widgets in the same amount of time it takes Machine B to produce 1 widget.. Since A+B take 4 hours to produce 200 widgets, the combined rate for A+B = w/t = 200/4 = 50 widgets per hour. To determine A's time to produce 200 widgets, we need to know A's rate. Question stem, rephrased: What is A's rate? Statement 1: Since B takes 5 hours to produce 50 widgets, B's rate = w/t = 50/5 = 10 widgets per hour. Thus, A's rate = (rate for A+B) - (B's rate) = 50-10 = 40 widgets per hour. SUFFICIENT. Statement 2: For every 1 widget produced by B, A produces 4 widgets. Thus: Of every 5 widgets produced when A+B work together, A produces 4 widgets, with the result that A produces 4/5 of the hourly number of widgets. Since the combined rate for A+B = 50 widgets per hour, we get: A's rate = (4/5)(50) = 40 widgets per hour. SUFFICIENT. 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: 986 messages Followed by: 27 members Upvotes: 59 AAPL wrote: Magoosh Working together, Machine A and Machine B can produce a total of 200 widgets in 4 hours. How many hours would it take Machine A, working alone, to produce 200 widgets? 1) Working alone, Machine B takes 5 hours to produce 50 widgets. 2) Machine A can produce 4 widgets in the same amount of time it takes Machine B to produce 1 widget. $$200\,\,{\rm{widgets}}\,\,\,\left\{ \matrix{ \,A\,\, = \,\,? \hfill \cr \,B\, \hfill \cr \,4\,\,\, \to \,\,\,{\rm{together}} \hfill \cr} \right.\,\,\,\,\,\left[ {\rm{h}} \right]$$ $$\left( 1 \right)\,\,B = 4 \cdot 5\,\,\,\,\, \Rightarrow \,\,\,\,{\rm{SUFF}}.\,\,\,\,\,\left( {{1 \over 4} = {1 \over A} + {1 \over {20}}\,\,\,\, \Rightarrow \,\,\,\,A\,\,{\rm{unique}}} \right)$$ $$\left( 2 \right)\,\,B = 4A\,\,\,\, \Rightarrow \,\,\,\,{\rm{SUFF}}.\,\,\,\,\,\left( {{1 \over 4} = {1 \over A} + {1 \over {4A}}\,\,\,\, \Rightarrow \,\,\,\,A\,\,{\rm{unique}}} \right)\,\,$$ This solution follows the notations and rationale taught in the GMATH method. Regards, Fabio. _________________ Fabio Skilnik :: https://GMATH.net (Math for the GMAT) or https://GMATH.com.br (Portuguese version) Course release PROMO : finish our test drive till 30/Dec with (at least) 50 correct answers out of 92 (12-questions Mock included) to gain a 50% discount! • 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 • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

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