Working together, 7 identical pumps can empty a pool in 6 hours. How many hours will it take 6 pumps to empty the same pool?  Choose the correct choice from the following answers
A) 6
B) 5
C) 4
D) 8
E) 7
The answer is E   7 pumps take 6 hours. 1 Pump will take 6*7 hours . Hence 6 pumps will take   (6*7)/6= 
<gadget id="calculator">  (6*7)/6</gadget>
<output>7</output>
7 hours
<result>E</result>
Working together, 7 identical pumps can empty a pool in 6 hours. How many hours will it take 6 pumps to empty the same pool?