Tank with a leak in bottom is filled in 15 hrs and without leak in 12 hrs. How much time leak will to empty the tank?

Question

A Tank with a leak in the bottom is filled in 15 hours and without leak it could have been filled in 12 hours. How much time it will take the leak to empty the tank?

Answer 1

60 hours.

It takes 3 hours to compensate for 15 hours of leakage. This means the refill rate is 5x the drainage rate.
It takes 12 hours to fill without leakage. 12 * 5 = 60 hours to drain completely.

Answer 2

it will take 60 hours

Answer 3

To fill the tank without leak =12 hrs
To fill the tank with leak =15 hrs
consider the capacity of the tank is 100%
To fill 25% of the tank without leak =12/4=3 hrs
To fill 20%of the tank with leak=15/5=3 hrs
hence, time taken to fill 25%of tank without leak=time taken to fill 20% of tank with leak
25%-20%=5% of tank is leaked for every 3 hrs
time taken to leak 100%of the tank=(100/5)*3=60 hrs