Pipes and Cistern Questions

A tap can fill a tank in 20 minutes. If a leakage is capable of emptying the tank in 60 minutes, the tank will be filled in

Two pipes namely A,B can fill a sump in 25 minutes and half an hour respectively and a pipe C can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity off the tank is

Pipes A, B and C are attached to an empty cistern. While the first two can fill the cistern in 4 and 10 hrs, respectively, the third can drain the cistern, when filled, in 6 hrs. If all the three pipes are opened simultaneously when the cistern is half-full, how many hours will be needed to fill the cistern?

A water tank has two holes. The 1st hole alone makes the tank empty in 3 min and 2nd hole alone makes the tank empty in 5 min. If water leaks out at a constant rate, how long in minutes does it take if both the holes together empty the tank?

Two pipes A and B can fill an empty cistern in 18 and 27 hours, respectively. Pipe C can drain the entire cistern in 45 hours when no other pipe is in operation. Initially, when the cistern was empty Pipe A and Pipe C were turned on. After a few Pipe A was turned off and Pipe B was turned on instantly. In all, it took 55 hours to fill the cistern. For how many hours was Pipe B turned on?

Out of three pipes the first two can fill an empty tank in 9 and 18 hours, respectively while the third can drain the filled tank in 15 hours. If all the three pipes are opened when the tank is empty, after how many hours will the tank be full?