Two pipes A and B can fill a tank in 15 min and 20 min respectively. Both the pipes are opened together but after 4 min, pipe A is turned off. What is the total time required to fill the tank?

Related Mcqs:

1. Two pipes can separately fill a tank in 20 and 30 hours respectively. Both the pipes are opened to fill the tank but when the tank is full, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?

   A. 18 hrs
   B. 16 hrs
   C. 15 hrs
   D. 12 hrs

2. A tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same during which the tank is filled by the third pipe alone. The second pipe fills the tank 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is?

   A. 6 hrs
   B. 10 hrs
   C. 15 hrs
   D. 30 hrs

3. Two pipes P and Q can fill a cistern in 12 min. and 15 min. respectively but a third pipe ‘R’ can empty the full tank in 6 min.  P and Q are kept open for 5 min. in the beginning and then ‘R’ is also opened.  In what time is the cistern emptied ?

   A. 30 min
   B. 35 min
   C. 40 min
   D. 45 min

4. Two pipes A and B can separately fill a cistern in 60 min and 75 min 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 50 min. In how much time, the third pipe alone can empty the cistern?

   A. 90 min
   B. 100 min
   C. 110 min
   D. 120 min

5. One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill tank in 36 min, then the slower pipe alone will be able to fill the tank in?

   A. 81 min
   B. 108 min
   C. 144 min
   D. 192 min

6. Two pipes A and B can separately fill a tank in 2 minutes and 15 minutes respectively. Both the pipes are opened together but 4 minutes after the start the pipe A is turned off. How much time will it take to fill the tank?

   A. 9 min
   B. 10 min
   C. 11 min
   D. 12 min

7. A tank can be filled by a pipe in 20 min. and by another pipe in 60 min.  Both the pipes are kept open for 10 min. and then the first pipe is shut off.  After this, the tank will be completely filled in__________?

   A. 10 min
   B. 20 min
   C. 30 min
   D. 40 min

8. Two pipes can fill a tank in 18 minutes and 15 minutes. An outlet pipe can empty the tank in 45 minutes. If all the pipes are opened when the tank is empty, then how many minutes will it take to fill the tank?

   A. 12
   B. 13
   C. 11
   D. 10

9. A cistern has two taps which fill it in 12 min. and 15 min.respectively   There is one outlet pipe in the cistern.  When all the taps & pipe are opened, the empty cistern is full in 20 min.  How long will the waste pipe (outlet) take to empty the full cistern ?

   A. 10 min
   B. 20 min
   C. 30 min
   D. 40 min

10. 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:

    A. 81 min.
    B. 108 min.
    C. 144 min.
    D. 192 min.