• NEW! FREE Beat The GMAT Quizzes
Hundreds of Questions Highly Detailed Reporting Expert Explanations
• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn
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: 15362 messages Followed by: 1866 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: 1449 messages Followed by: 32 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 :: GMATH method creator ( Math for the GMAT) English-speakers :: https://www.gmath.net Portuguese-speakers :: https://www.gmath.com.br • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • 5 Day FREE Trial Study Smarter, Not Harder 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 Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • Magoosh Study with Magoosh GMAT prep Available with Beat the GMAT members only code • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to \$200

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

• 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

### Top First Responders*

1 Brent@GMATPrepNow 41 first replies
2 Ian Stewart 37 first replies
3 Jay@ManhattanReview 32 first replies
4 GMATGuruNY 26 first replies
5 Scott@TargetTestPrep 14 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 Scott@TargetTestPrep

Target Test Prep

199 posts
2 Max@Math Revolution

Math Revolution

92 posts
3 Brent@GMATPrepNow

GMAT Prep Now Teacher

74 posts
4 GMATGuruNY

The Princeton Review Teacher

45 posts
5 Ian Stewart

GMATiX Teacher

43 posts
See More Top Beat The GMAT Experts