question_answer

An inlet pipe can fill a tank in 8 hours. An outlet pipe can empty the same tank in 12 hours. Initially the tank is completely empty. At this point of time, the inlet pipe is connected to the tank. After 3 hours, the outlet pipe is also connected to the tank. After how much time from the beginning, will the tank be full?

A) 15 hours

B) 18 hours

C) 20 hours

D) 24 houre

E) 22 hours