nalinnair wrote:
Five machines at a certain factory operate at the same constant rate. If four of these machines, operating simultaneously, take 30 hours to fill a certain production order, how many fewer hours does it take all five machines, operating simultaneously, to fill the same production order?
(A) 3
(B) 5
(C) 6
(D) 16
(E)24
4 machines take -> 30 hours
1 machine takes -> 30*4 hours
5 machines take -> 30*4/5 hours
Difference = 30*4/5-30= 6hours
Answer (C) 6hours
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