Given: A tap can fill a pond in 24 hours, and due to a leakage in the bottom it is filled in 36 hours Concept: If a tap can fill a tank in x hours, then the tank filled by the tap in 1 hour = 1/x of the total tank. Calculation: Part of pond emptied by leak in an hours =
1
36
−
1
24
⇒
2−3
72
=−172 Time taken in emptying the full pond = 72 hours Required time =72/2=36 hours ∴ The required time is 36 hours.