An electric pump can fill a tank in 6 hours. Because of a leak in the tank, it took 12hours to fill the tank. If the tank is full, how much time will the leak take to empty it? Answers:	A) 10hours	B) 12hours	C) 8hours	D) 5hours	E) 15hours
Work done by the leak in 1 hour = 1/6 - 1/12 = 1/12   The leak will empty the tank in 12hours   Answer is 12hours
<result>B</result>
An electric pump can fill a tank in 6 hours. Because of a leak in the tank, it took 12hours to fill the tank. If the tank is full, how much time will the leak take to empty it?