How much water flows in or out during 1 hour? If the result indicates that the tank will fill in x hours, then
1/5 + 1/6 - 1/12 = 1/x
Now just solve for x
Pipes A and B can fill a tank in 5 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, how long will it take to fill the tank from empty to full?
1 answer