The pump can fill the tank in 3 hours ∴ Part of the tank filled by the pump in 1 hour = 1/3 Let, the leak can drain all the water in ‘x’ hours ∴ Part of the tank leaked by the drain in 1 hour = 1/x Given, Because of a leak, the pump took 3
1
5
hours=
16
5
hours to fill the tank 1/3 - 1/x = 5/16 ⇒ 1/x = 1/3 - 5/16 ⇒ 1/x = (16 - 15)/46 ⇒ 1/x = 1/48 ⇒ x = 48 hours