There pipes A, B and C, can fill a tank in 10, 15, and 18 hours, respectively. A and C are opened for 5 hours, then only pipe A is closed and B is opened at the same time (with C). The total time taken to fill the tank completely is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. .
Given:
Time taken by pipe A to fill the tank = 10 hours
Time taken by pipe B to fill the tank = 15 hours
Time taken by pipe C to fill the tank = 18 hours
Explanation:
Capacity of the tank = LCM of 10 , 15, and 18 = 90
Efficiency of A (90/10) = 9
Efficiency of B (90/15) = 6
Efficiency of C (90/18) = 5
A and C five hours work = (9 + 5) × 5
⇒14 × 5 = 70
Remaining capacity = 90 - 70 = 20
Remaing work done by B and C = 20/(6 + 5)
⇒ 20/11=
Total days = 5 + =