Two pipes A and B can fill a water tank in 20 and 24 minutes respectively and a third pipe C can empty at the rate of 3 gallons per minute. If A, B and C opened together fill the tank in 15 minutes, the capacity (in gallons) of the tank is?

Two pipes P and Q, would fill a cistern in 18 and 24 minutes respectively. Both pipes being opened, find when the first pipe must be turned off so that the cistern may be just filled in 12 minutes?

An empty tank can be filled by pipe. A in 4 hours and by pipe B in 6 hours. If the two pipes are opened for 1 hour each alternatively with first opening pipe A, then the tank will be filled in.

A swimming pool has 3 drain pipes. The first two pipes A and B, operating simultaneously, can empty the pool in half the time that C, the 3rd pipe, alone takes to empty it. Pipe A, working alone, takes half the time taken by the pipe B. Together they take 6 hours 40 minutes to empty the pool. Time taken by pipe A to empty the pool, in hours, is

Pipes A and B can fill a cistern in 8 and 24 minutes respectively. They are opened on alternate minutes.  Find in how many minutes, the cistern shall be full?

A water tank has three taps A, B and C. Tap A, when opened, can fill the water tank alone in 4 hours. Tap B, when opened, can fill the water tank alone in 6 hours and tap C, when opened, can empty the water tank alone in 3 hours. If taps A, B and C are opened simultaneously how long will it take to fill the tank completely ?

One pipe fills a water tank three times faster than another pipe. If both the pipes together can fill the empty tank in 36 minutes, then how much time will the slower pipe alone take to fill the tank?

Pipe P can fill a tank 12 hours and pipe Q can fill it in 15 hours separately. A third pipe R can empty it in 20 hours. Initially pipe P was opend after 1 hour pipe Q was opend and then after 1 hour when Q was opend pipe R was also opend. In how many hours the tank will be full ? 

A cistern is normally filled in 8 hours but takes another 2 hours longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty it in :

One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in :