GMATPrep Test 1 #2_PS Rates Basic #21

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GMATPrep Test 1 #2_PS Rates Basic #21

by kwah » Sun Mar 11, 2012 8:32 pm
What is the most efficient way to achieve the result for question attached?

Answer: B

Thanks,
K
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by Anurag@Gurome » Sun Mar 11, 2012 8:47 pm
kwah wrote:What is the most efficient way to achieve the result for question attached?

Answer: B

Thanks,

K
Let the rate of 1 machine = x
Then rate of 10 machines = 10x
It is given that work = 16 * 10x
Let time taken by 8 machines = T
Then same work = 8x * T
So, 16 * 10x = 8x * T implies T = 20 hrs

The correct answer is B.
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by dhiren8182 » Sun Mar 11, 2012 10:04 pm
I solved by formulae:
W1T1=W2T2
10*16=8*x
so x=20
therefore 20 hrs required to compelte job