A pump can fill a tank with water in 6 hours. Because of a leak, it took 7 hours to fill the tank. The leak can drain all the water in ? Choose the correct choice from the following answers
A) 15hr 10min
B) 16hr 20min
C) 17hr 30min
D) 42hr
E) 14hr 25min
Work done by the leak in 1 hour = 1/6 - 1/7 = 1/42   Leak will empty the tank in 42 hrs   Answer is 42hr
<result>D</result>
A pump can fill a tank with water in 6 hours. Because of a leak, it took 7 hours to fill the tank. The leak can drain all the water in ?