A cistern has a hole in the bottom through which the water is leaking. A tap can fill the cistern in 3 hours and the hole in the bottom can empty the fully filled cistern in 5 hours. If both the tap and the hole are open. then what will be the time taken to completely fill the empty cistern?
Given:
A tap can fill the cistern = 3 hours.
A hole empty the fully filled cistern = 5 hours.
Formula Used:
Total work = Efficiency time
Solution:
Total capacity = LCM of 3, 5 = 15
Efficiency of Tap =
Efficiency of hole at bottom(negative) =
Combine Efficiency = 5 +(-3) = 2
Total time taken to fill the tank:
=
Thus, time taken is 7.5 hours
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