An electric pump can fill a tank in 3 hours. Because of a leak in the tank, it took 3 hours 30 min to fill the tank. In what time the leak can drain out all the water of the tank and will make tank empty ?
Answer: D
We can get the answer by subtracting work done by leak in one hour by subtraction of
filling for 1 hour without leak and with leak, as
Work done for 1 hour without leak = 1/3
Work done with leak =
So tank will be empty by the leak in 21 hours.