A pipe can fill a tank in 15 hours. Due to a leakage in the bottom, it is filled in 20 hours. If the tank is full, how much time will the leakage take to empty it?

60 hours

A is inlet pipe & B is a leakage.

If the capacity of the tank is taken as 60, then ;

∴ efficiency of B = 4 - 3 = 1

∴ Time taken by leakage to empty a full tank = \(\frac{60}{1}\) = 60 hrs.