An electric pump can fill a tank in 4 hours. Because of a leak in the tank, it took 8hours to fill the tank. If the tank is full, how much time will the leak take to empty it?  Choose the most appropriate option:  A) 10 hours  B) 12 hours  C) 8 hours  D) 5 hours  E) 15 hours

Rationale: work done by the leak in 1 hour = 1 / 4 - 1 / 8 = 1 / 8 the leak will empty the tank in 8 hours answer is c
Answer: C