A pump can fill a tank with water in 8 hours. Because of a leak, it took 9 hours to fill the tank. The leak can drain all the water in ?  Pick one
A) 15hr 10min
B) 16hr 20min
C) 17hr 30min
D) 72hr
E) 14hr 25min
Work done by the leak in 1 hour = 1/8 - 1/9 = 1/72   Leak will empty the tank in 72 hrs =   Answer is 72hr
<result>D</result>
A pump can fill a tank with water in 8 hours. Because of a leak, it took 9 hours to fill the tank. The leak can drain all the water in ?