A cistern has two taps which fill it in 12 minutes and 15 minutes respectively. There is also a waste pipe in the cistern. When all the three are opened, the empty cistern is full in 20 minutes. How long will the waste pipe take to empty the full cistern?

A cistern has two taps which fill it in 12 minutes and 15 mintues respectively . There is also a waste pipe in the cistern. When all the pipes are opened , the empty cistern is filled in 20 mintues. How long will the waste pipe take to empty a full cistern ?

Two pipes A and B can fill a cistern in 24 minutes and 30 minutes, respectively. There is also an outlet C. If all the three pipes are opened together, the cistern is filled in 20 minutes. How much time will be taken by C to empty the full cistern?

Two pipes A and B can separately fill a cistern in 40 minutes and 30 minutes respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened, then the cistern is full in 20 minutes. In how much time, the third pipe alone can empty the cistern?

Two pipes A and B can separately fill a cistern in 60 minutes and 75 minutes respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened then the cistern is full in 50 minutes. In how much time, the third pipe alone can empty the cistern? 90 m in b. 100 m in c. 110 m in d. 120 m in

Two pipe A and B can separately fill a cistern in 60 minutes and 75 minutes respectively . There is a third pipe at the bottom of the cistern to empty it, if all the three pipes are simultaneously opened, then the cistern is filled in 50 minutes . In how much time can the third pipe alone empty the cistern ?

A cistern has two inlets A and B which can fill it in 12 minutes and 15 minutes respectively. An outlet C can empty the full cistern in 10 minutes.If all the three pipes are opened together in the empty tank,how much time will they take to fill the tank completely?