Mathematics (Pipe and Cistern নল এবং জলাধার)

1) A hollow iron pipe is 10 cm long and its external diameter is 18 cm. If the thickness of the pipe is 2 cm
and iron weighs 8.5 g/cm , then the weight of the pipe from the following is closest to

2) If an inlet pipe fills a tank in 4 hours and an outlet pipe empties it in 9 hours, how long will it take for the tank to fill if both pipes are opened simultaneously?

3) A cistern has two pipes which can fill it in 15 minutes and 25 minutes respectively. Both are opened together, but due to a leakage at the bottom, it takes 20 minutes to fill the cistern. How long will it take for the leak to empty the cistern alone?

4) A cistern can be filled by a pipe in 4 hours. Due to a leak at the bottom, it takes 4.5 hours to fill the cistern. If the cistern is empty, how long will it take to fill it due to a leak at the bottom?

5) Pipe A can fill a tank in 6 hours while Pipe B can fill it in 8 hours. Pipe C can empty the tank in 12 hours. If all three pipes are opened together, how long will it take to fill the tank?

6) Two pipes A and B can fill a cistern in 20 minutes and 30 minutes respectively. A third pipe C can empty the tank in 15 minutes. If the three pipes are opened together, how long will it take for the tank to fill?

7) A tank is filled up by a pipe A in 5 minutes while it is emptied by a pipe
B in 10 minutes. When the tank is half-filled up two pipes are opened
simultaneously. Find the time required so that ¾th of the tank is filled up

8) A pipe can fill a cistern in 20 minutes whereas the cistern when full can be emptied by a leak in 28
minutes. When both are opened,the time takento fill the cistern is

9) Two inlet pipes can separately fill a cistern completely in § hours and 10 hours, tespectively. They are operated for 2
houss, after which the second pipe is closed, and an outlet pipe which can drain out water from the full cistern in 20
hours is opened. How much time will it take to il the cistern completely from the instant of opening the ontlet pipe?

10) Two pipes can fill a tank in 12 hours and 10 hours respectively and a third pipe can empty in 20 hours, if all the pipes are opened together, then the tank will be filled in