Pipe A, B and C together can fill a tank in 9 minutes. Pipe B and C together can fill the same tank in 12 minutes. Pipe C and A together can fill the same tank in 18 minutes. In how much time (in minutes) pipe B alone can fill the tank?
Show answer & explanation
Correct answer: B
Explanation
Given:
A + B + C fill the tank = 9 minutes
B + C fill the tank = 12 minutes
C + A fill the tank = 18 minutes
A + B + C = 1/9
B + C = 1/12
A = (A + B + C) − (B + C)
= 1/9 − 1/12
= (4 − 3) / 36
= 1/36
C + A = 1/18
C = 1/18 − 1/36
= (2 − 1) / 36
= 1/36
Now,
B + C = 1/12
B + 1/36 = 1/12
B = 1/12 − 1/36
= (3 − 1) / 36
= 2/36
= 1/18
Time = 18 minutes