Pipes And CisternsPractice Questions

A swimming pool has three filling pipes M, N, and O. Pipe M can fill the pool in 20 hours, pipe N can fill it in 30 hours, and pipe O can fill it in 60 hours. If all three pipes are opened simultaneously, how long will it take to fill the empty pool?

A water reservoir has two inlet pipes P and Q, and one outlet pipe R. Pipe P fills the reservoir in 15 hours, pipe Q fills it in 20 hours, and pipe R can empty the full reservoir in 12 hours. If all three pipes are opened together when the reservoir is empty, how long will it take to fill the reservoir completely?

A cistern can be filled by pipe S in 8 hours and by pipe T in 12 hours. There is also a drain pipe U that can empty the cistern in 6 hours. If the cistern is initially empty and all pipes are opened simultaneously, what will happen?

Two pipes A and B can fill a tank in 12 and 18 minutes respectively. If both pipes are opened together, how long will it take to fill the tank?

A tank has an inlet pipe that can fill it in 6 hours. It also has an outlet pipe that can empty the full tank in 8 hours. If both pipes are opened simultaneously when the tank is empty, how long will it take to fill the tank?

Three pipes X, Y, and Z can fill a cistern in 10, 15, and 30 hours respectively. All three pipes are opened together, but after 2 hours, pipe Z is closed. How much more time will be needed to fill the cistern?

A pipe can fill a tank in 20 hours. Due to a leak at the bottom, it takes 25 hours to fill the tank. If the tank is full, how long will the leak alone take to empty it?

Two pipes can fill a pool in 8 and 12 hours respectively. A third pipe can empty the pool in 6 hours. If all three pipes work together, how long will it take to fill the empty pool?

A tank has 4 inlet pipes. Pipes A, B, C can fill the tank individually in 2, 3, and 6 hours respectively. Pipe D can empty the full tank in 4 hours. If all pipes are opened together, how long will it take to fill the tank?

Pipe P can fill a tank in 16 hours and pipe Q can fill it in 24 hours. Both pipes are opened together for 4 hours, then pipe P is closed. How much more time will pipe Q alone take to fill the remaining tank?