Question
Tap P can fill the tank in 5 hours and Tap Q can empty it in 7(1/2) hours. Tap P starts filling and they opened for 1 hour each alternatively. In what time will the tank be full?
Solution
2 Hours = 1 work done 
Last work will be done by P Therefore, 15 -3 = 12 
More Pipes and cisterns Questions
- Pipe P can fill a cistern in 12 hours and pipe Q in 20 hours. If both the pipes are opened in an empty cistern, how much time will they take to fill it?
- Pipe ‘A’ can fill a tank in 12 hours while pipe ‘B’ takes 15 hours to empty it. Pipe ‘A’ is opened alone when the tank was empty and after 10 hours pipe ‘B...
- Tap A can fill a tank in 20 hours and tap B can emptied it is 25 hours. Tap A starts filling and they opened for 1 hour each alternatively in what time wil...
- Tap A can fill a tank in 10 hours. Tap B can fill 12.5% part of the same tank in 2 hours, whereas Tap C can alone empty a tank in ‘x’ hours. 3/7 part of th...
- A tank has two inlet pipes A and B and an outlet pipe C. Pipe A can fill the tank in 6 hours, and Pipe B can fill it in 8 hours. Pipe C can empty the full ...
- Tap ‘A’ and tap ‘B’ can fill a tank in 42 hours and 30 hours, respectively. If both taps are opened together, then find the time after which tap ‘A’ must b...
- An inlet pipe can fill a tank in 18 minutes, while an outlet pipe can empty it in 27 minutes. Sujata starts the inlet pipe at 6 a.m., but the outlet pipe i...
- A leak in the bottom of the tank can empty the full tank in 18 hours. An inlet pipe fills water at the rate of 12 liters a minutes. When the tank is full, ...
- Pipe ‘A’ takes 15 minutes to fill a tank. Pipe ‘B’ takes 25 minutes to empty the same tank. If pipe ‘B’ is opened 11 minutes after pipe ‘A’, then find the ...
- Pipe M can fill a tank in 10 hours, and pipe N can do the same in 30 hours. Pipe O can drain half the tank in 6 hours. If all pipes are opened at once, how...
