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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 marzipan factory has two machines producing marzipan. tagged by: AAPL ##### This topic has 2 expert replies and 1 member reply ### Top Member ## A marzipan factory has two machines producing marzipan. ## Timer 00:00 ## Your Answer A B C D E ## Global Stats Difficult Economist GMAT A marzipan factory has two machines producing marzipan. Every day, the two machines operate constantly from 08:00 to 18:00, and produce together N kg of marzipan. What percent of the total amount of marzipan produced by machines W and D together was produced by machine W? 1) Working alone, it takes machine W twenty-five hours to produce (N/2) kg of marzipan. 2) Machine W alone produces N/2 kg of marzipan in double the time it takes machine D alone to produce N kg of marzipan. OA D ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15314 messages Followed by: 1863 members Upvotes: 13060 GMAT Score: 790 AAPL wrote: Economist GMAT A marzipan factory has two machines producing marzipan. Every day, the two machines operate constantly from 08:00 to 18:00, and produce together N kg of marzipan. What percent of the total amount of marzipan produced by machines W and D together was produced by machine W? 1) Working alone, it takes machine W twenty-five hours to produce (N/2) kg of marzipan. 2) Machine W alone produces N/2 kg of marzipan in double the time it takes machine D alone to produce N kg of marzipan. Statement 1: Let N = 50 kg. Since W and D produce the entire 50 kg over the 10 hours between 8:00 and 18:00, the combined rate for W and D = 50/10 = 5 kg per hour. Since W takes 25 hours to produce N/2 = 25 kg, W's rate alone = w/t = 25/25 = 1 kg per hour. Of every 5 kg produced each hour when W and D work together, W produces 1 kg. Thus: (W's hourly work)/(total hourly work) = 1/5 = 20%. SUFFICIENT. Statement 2: Let N = 4 kg and D's time for N kg = 1 hour. Thus, D's rate = (4 kg)/(1 hour) = 4 kg per hour. Since W produces N/2 kg (2 kg) in twice D's time for N kg (2 hours), W's rate = (2 kg)/(2 hours) = 1 kg per hour. Combined rate for W and D working together = 1+4 = 5 kg per hour. Of every 5 kg produced each hour when W and D work together, W produces 1 kg. Thus: (W's hourly work)/(total hourly work) = 1/5 = 20%. 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. ### Top Member Legendary Member Joined 29 Oct 2017 Posted: 933 messages Followed by: 4 members Hi, I have a doubt. 2) Machine W alone produces N/2 kg of marzipan in double the time it takes machine D alone to produce N kg of marzipan. How is option B sufficient? it doesn't state anything about the time for either machine W or machine D; it only compares the work of two machines. I feel the answer should be A. ### GMAT/MBA Expert GMAT Instructor Joined 25 May 2010 Posted: 15314 messages Followed by: 1863 members Upvotes: 13060 GMAT Score: 790 swerve wrote: Hi, I have a doubt. 2) Machine W alone produces N/2 kg of marzipan in double the time it takes machine D alone to produce N kg of marzipan. How is option B sufficient? it doesn't state anything about the time for either machine W or machine D; it only compares the work of two machines. I feel the answer should be A. The prompt states: Every day, the two machines operate constantly from 08:00 to 18:00. As shown in my post above, Statement 2 yields the following rate ratio: (W alone) : (W and D together) = 1:5. The rate ratio indicates that -- of every 5 kg produced when W and D work together from 8:00 to 18:00 -- W will produce 1 kg. Thus: (W's hourly work)/(total hourly work) = 1/5 = 20%. SUFFICIENT. _________________ 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! 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