Two pipes A and B can fill a tank in 60 minutes and 75 minutes respectively. There is also an outlet C. If A, B and C are opened together, the tank is full in 50 minutes. How much time will be taken by C to empty the full tank?

A cistern can be filled by two pipes P and Q in 4 hours and 6 hours respectively. When full, the tank can be emptied by pipe R in 8 hours. If all the taps be turned on at the same time, the cistern will be full in

A mason can build a tank in 12h. After working for 6h, he took the help of a boy and finished the work in another 5h. The time that the boy will take alone to complete the work is

Three pumps working 8 hours a day can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 days.

16 pipes are fitted in a tank. Some are inlet pipes and some are outlet pipes. Each inlet pipe can fill the tank in 6 hours and each outlet pipe can empty in 12 hours. If all pipes are opened together, then tank will full in 6 hour. Find the number of inlet pipes.