A tank is fitted with two taps. The first tap can fill the tank completely in 45 minutes and the second tap can empty the full tank in one hour. If both the taps are opened alternately for one minute, then in how many hours the empty tank will be filled completely?

Two pipes P and Q would fill a cistern in 24 hours and 32 hours respectively. If both pipes are opened together, find when the pipe “P” must be turned off so that the cistern may be just filled in 16 hours-

A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?

A pipe of diameter ‘d’ can drain a certain water tank in 40 minutes. The time taken by a pipe of diameter ‘2d’ for doing the same job in: 

A cistern has 3 pipes A, B and C. A and B can fill it in 3 and 4 hours respectively, and C can empty it in 1 hour. If the pipes are opened at 3 p.m., 4 p.m. and 5 p.m. respectively on the same day, the cistern will be empty at-

 Pipe A alone & pipe B alone can fill the same tank in 5 hours and 4 hours respectively. If the ratio of efficiency of pipe A & B together to that of pipe C alone is 9:2, then find time taken by pipe C alone to fill the same tank?

A tank can be filled with water by two pipes A and B together in 36 minutes. If the pipe B was closed after 30 minutes, the tank is filled in 40 minutes. The pipe B can alone fill the tank in?

Two pipe A and B can fill a tank in 16 hrs and 12 hrs respectively. The capacity of the tank is 240 litres. Both the pipes are opened simultaneously and closed after 2 hrs. How much more water (In Liters) needed to fill the tank?