| | Question 9

Two pipes A and B independently can fill a tank in 20 hours and 25 hours. Both are opened together for 5 hours after which the second pipe is turned off. What is the time taken by first pipe alone to fill the remaining portion of the tank?
(A) 11 hours
(B) 13 hours
(C) 15 hours
(D) 17 hours


Answer: (A)

Explanation: Total unit water = LCM(20, 25) = 100 unit
A’s efficiency = 100/20 = 5 unit/hour
B’s efficiency =100/25 = 4 unit/hour
After 5 hour the water filled by A and B together = 5 x 9 =45 unit
Remaining unit = 100 – 45 = 55 unit
Time taken by A alone = 55/5 = 11 hours

Quiz of this Question
Please comment below if you find anything wrong in the above post



My Personal Notes arrow_drop_up


Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.