Mettl Questions on Pipes and Cisterns

A cistern can be filled by a tap in 4 hours while it can be 

emptied by another tap in 9 hours. If both the taps are opened

simultaneously, then after how much time cistern will get filled ?

Two pipes A and B can fill a tank in 15 minutes and 20 minutes

respectively. Both the pipes are opened together but after 

4 minutes, pipe A is turned off. What is the total time 

required to fill the tank?

A large tanker can be filled by two pipes A and B in 60 minutes

and 40 minutes respectively. How many minutes will it take to 

fill the tanker from empty state if B is used for half the time

and A and B fill it together for the other half?

Three pipes A, B and C can fill a tank in 6 hours. 

After working at it together for 2 hours, C is closed and A 

and B can fill the remaining part in 7 hours. 

The number of hours taken by C alone to fill the tank is:

Three pipes A, B and C can fill a tank in 6 hours. 

After working at it together for 2 hours, C is closed and A

and B can fill the remaining part in 7 hours. 

The number of hours taken by C alone to fill the tank is:

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 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?

Three taps A, B and C can fill a tank in 12, 15 and 20 hours

respectively. If A is open all the time and B and C are open 

for one hour each alternately, the tank will be full in:

Three pipes A, B and C can fill a tank in 6 hours. 

After working at it together for 2 hours, C is closed and 

A and B can fill the remaining part in 7 hours. 

The number of hours taken by C alone to fill the tank is:

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 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?

One pipe can fill a tank 6 times as fast as another pipe. If

together the two pipes can fill the tank in 22 minutes, 

then the slower pipe alone will be able to fill the tank in:

One pipe can fill a tank 6 times as fast as another pipe.

If together the two pipes can fill the tank in 22 minutes, 

then the slower pipe alone will be able to fill the tank in?

One pipe can fill a tank three times as fast as another pipe.

If together the two pipes can fill the tank in 36 minutes, 

then the slower pipe alone will be able to fill the tank in: