Correct Answer - Option 4 : 14 hours

Given:

Time taken by a tap fills the tank with water = 2 hours

Time taken by a leakage = 2,1/3

Formula used:

Efficiency = Work/Time

Calculation:

Part of the tank filled by the pump in 1 hour = 1/2

Total part of the tank filled by the pump and leak in 1 hour = 1/(7/3) = 3/7

so part of the tank emptied by the leak in 1 hour = 1/2 - 3/7

⇒ (7 - 6)/14 = 1/14

∴ The leak will empty the tank in 14 hours