An inlet pipe takes 8 hours to fill a tank. An outlet pipe takes 12 hours to empty it. If both pipes are opened simultaneously, in how many hours will the tank be filled?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 24
An inlet pipe takes 8 hours to fill a tank. An outlet pipe takes 12 hours to empty it
Let the capacity of tank = L.C.M of 8 and 12 = 24L
Efficiency = total work/time
Efficiency of inlet pipe = 24/8 = 3
Efficiency of outlet pipe = 24/12 = 2
If both pipes are opened simultaneously then net efficiency = 3 - 2 = 1
so time taken to fill tank = 24/1 = 24hr.