Q28 of 28 Page 11

A cistern can be filled by a tap in 4 hours and emptied by an outlet pipe in 6 hours. How long will it take to fill the cistern if both the tap and the pipe are opened together?

Given,


Inlet tap can fill a cistern in = 4 hours


Outlet tap can emptied it in = 6 hours


∵ Work done by inlet tap in 1 hour =


∵ Work done by outlet pipe in 1 hour =


∴ Work done by both pipe in 1 hour =


Hence, both the tap can filled it in =


More from this chapter

All 28 →
24

A cistern can be filled by one tap in 8 hours, and by another in 4 hours. How long will it take to fill the cistern if both taps are opened together?

 25

Two taps A and B can fill an overhead tank in 10 hours and 15 hours respectively. Both the taps are opened for 4 hours and then B is turned off. How much time will A take to fill the remaining tank?

 26

A pipe can fill a cistern in 10 hours. Due to a leak in the bottom it is filled in 12 hours. When the cistern is full, in how much time will it be emptied by the leak?

 27

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