Let the total capacity of the cistern is 24 units. (LCM) So, the efficiency of the pipe A and pipe B are 2 units / hour and 3 units / hour respectively. ATQ Total time taken to fill the cistern =
24
2+3
+
12
60
= 5hour Efficiency of leakage = (2+3)−
24
5
units / hour =
1
5
units / hour ∴ time taken by leakage to empty the full tank alone =