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?

Pipes and Cisterns 26/06/2020

A. 10 min 20 sec
B. 11 min 45 sec
C. 12 min 30 sec
D. 14 min 40 sec

Explanation:

Part filled in 4 minutes = 4(1/15 + 1/20) = 7/15

Remaining part = 1 – 7/15 = 8/15
Part filled by B in 1 minute = 1/20
1/20 : 8/15 :: 1 ; x
x = 8/15 * 1 * 20 = 10 2/3 min = 10 min 40 sec.
The tank will be full in (4 min. + 10 min. 40 sec) = 14 min 40 sec.

Related Mcqs:

    Two pipes A and B can fill a cistern in 20 and 30 minutes respectively, and a third pipe C can empty it in 40 minutes. How long will it take to fill the cistern if all the three are opened at the same time?
    A. 19 1/7 min B. 15 1/7 min C. 17 1/7 min D. 7 1/7 min...
    Two pipes P and Q can fill a cistern in 12 and 15 minutes respectively. Both are opened together, but at the end of 3 minutes the first is turned off. How much longer will the cistern take to fill?
    A. 9 1/4 min B. 11 1/4 min C. 7 1/4 min D. 8 1/2 min...
    A cistern which could be filled in 9 hours takes one hour more to be filled owing to a leak in its bottom. If the cistern is full in what time will the leak empty it?
    A. 45 hrs B. 60 hrs C. 75 hrs D. 90 hrs...
    Two pipes A and B together can fill a cistern in 4 hours. Had they been opened separately, then B would have taken 6 hours more than A to fill cistern. How much time will be taken by A to fill the cistern separately?
    A. 1 hr B. 2 hrs C. 6 hrs D. 8 hrs...
    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....

Leave a Reply

Your email address will not be published. Required fields are marked *