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Machine A can produce toys at a constant rate of 2 units per hour and
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21 Feb 2017, 23:59
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Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours? A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs
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Re: Machine A can produce toys at a constant rate of 2 units per hour and
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22 Feb 2017, 00:35
AustinKL wrote: Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours?
A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs A Produces @ 2 Units per hour B Produces @ 5 Units per hour Greatest Number of Hours of A and B together will be obtained when the remaining job (job done by one machine while working alone) is done by the individual machines (which is A in this case)A and B together can produce = (2+5) = 7 Units per Hour Let's start with biggest option If both A&B work for 9 Hours the production = 7*9 = 63 and the remaining work (8863=25 units) can be finished in 11 hours (1 hour of B i.e. 5 units and 10 hours of A i.e. 20 units) Hence Correct OptionAnswer: Option E
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Re: Machine A can produce toys at a constant rate of 2 units per hour and
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22 Feb 2017, 00:57
GMATinsight wrote: AustinKL wrote: Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours?
A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs A Produces @ 2 Units per hour B Produces @ 5 Units per hour Greatest Number of Hours of A and B together will be obtained when the remaining job (job done by one machine while working alone) is done by the individual machines (which is A in this case)A and B together can produce = (2+5) = 7 Units per Hour Let's start with biggest option If both A&B work for 9 Hours the production = 7*9 = 63 and the remaining work (8863=25 units) can be finished in 11 hours (1 hour of B i.e. 5 units and 10 hours of A i.e. 20 units) Hence Correct OptionAnswer: Option E Dear GMATinsight, Could you share with me why shall we consider the remaining job?
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Re: Machine A can produce toys at a constant rate of 2 units per hour and
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22 Feb 2017, 01:06
AustinKL wrote: GMATinsight wrote: AustinKL wrote: Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours?
A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs A Produces @ 2 Units per hour B Produces @ 5 Units per hour Greatest Number of Hours of A and B together will be obtained when the remaining job (job done by one machine while working alone) is done by the individual machines (which is A in this case)A and B together can produce = (2+5) = 7 Units per Hour Let's start with biggest option If both A&B work for 9 Hours the production = 7*9 = 63 and the remaining work (8863=25 units) can be finished in 11 hours (1 hour of B i.e. 5 units and 10 hours of A i.e. 20 units) Hence Correct OptionAnswer: Option E Dear GMATinsight, Could you share with me why shall we consider the remaining job? Because we need to ensure that work is done in 20 Hours which is a mentioned fact which needs to be abide by
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Machine A can produce toys at a constant rate of 2 units per hour and
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22 Feb 2017, 05:03
Quote: Because we need to ensure that work is done in 20 Hours which is a mentioned fact which needs to be abide by Dear GMATinsight, However, the question is asking about greatest possible hours so that machine A & B can produce 88 units and not the remaining.
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Re: Machine A can produce toys at a constant rate of 2 units per hour and
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22 Feb 2017, 06:32
AustinKL wrote: Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours?
A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs Hi, This problem can be thought as a three machine problem. Let's call A+B together as Machine C. Let Machine A works for \(x\) hrs @ 2unit/hr Machine B works for \(y\) hrs @ 5 units/hr, and Machine C works for \(z\) hrs @ 7 units/hr Equation for time constraint: \(x + y + z = 20\)  (1) Production constraint: \(2x + 5y + 7z = 88\)  (2) Eqn(2)  2*Eqn(1) \(2x + 5y + 3z  2x 2y 2z = 88  40 \Rightarrow 3y + 5z = 48 \Rightarrow z = \frac{48  3y}{5}\) Maximum possible integral value of \(z = 9\) for \(y = 1\) Answer: 9hrs (E). Plug in the value of z and y in Eqn (1), we get x = 11. These values satisfy both the equations. Thanks.



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Machine A can produce toys at a constant rate of 2 units per hour and
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22 Feb 2017, 10:45
AustinKL wrote: Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours?
A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs quick and dirty approach: let x=number of units produced by A and B x/7+(88x)/2=20 hrs x≈67 units 67/7≈9 hrs 9 E



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Machine A can produce toys at a constant rate of 2 units per hour and
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02 May 2017, 21:12
ziyuen wrote: Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours?
A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs OFFICIAL EXPLANATION If machine A produces toys for "a" hours and machine B produces toys for "b" hours, and both machine A and B produce toys for "c" hours at the same time, you get \(a+b+c=20\) (1). \(2a+5b+(2+5)c=88\) \(2a+5b+7c=88\) (2) Multiply (1) by 2, \(2a+2b+2c=40\) (3). Equation (2) minus Equation (3), \(3b+5c=48\) (4) (a, b, c) = (10, 1, 9), (8, 6, 6), (6, 11, 3) Among these, the possible maximum value of c is 9. Answer : E
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Re: Machine A can produce toys at a constant rate of 2 units per hour and
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05 May 2017, 08:41
a=2 b=5 a+b=7 option checking from higher value option E 7*9=63 remain=8863=25 2*10+5*1=25 answer:E



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Re: Machine A can produce toys at a constant rate of 2 units per hour and
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06 May 2017, 03:04
GMATinsight wrote: AustinKL wrote: Machine A can produce toys at a constant rate of 2 units per hour and machine B can produce toys at a constant rate of 5 units per hour. If at least one of either machine A or machine B produces toys, what is the greatest possible hours when machine A and machine B work together at their constant rates so that two machines, A and B, can produce 88 units of toys in 20 hours?
A. 5hrs B. 6hrs C. 7hrs D. 8hrs E. 9hrs A Produces @ 2 Units per hour B Produces @ 5 Units per hour Greatest Number of Hours of A and B together will be obtained when the remaining job (job done by one machine while working alone) is done by the individual machines (which is A in this case)A and B together can produce = (2+5) = 7 Units per Hour Let's start with biggest option If both A&B work for 9 Hours the production = 7*9 = 63 and the remaining work (8863=25 units) can be finished in 11 hours (1 hour of B i.e. 5 units and 10 hours of A i.e. 20 units) Hence Correct OptionAnswer: Option E Good question, bad wording. Agree?
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Re: Machine A can produce toys at a constant rate of 2 units per hour and
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