A pipe can fill a tank in 6 hours, another pipe can fill it in 8 hours, but a leak can empty it in 12 hours. If all work together, how long will it take to fill the tank?
Show answer & explanation
Correct answer: B
Explanation
Given:
Time taken by the first pipe to fill the tank = 6 hours
Time taken by the second pipe to fill the tank = 8 hours
Time taken by the leak to empty the tank = 12 hours
According to the formula:
Net work rate = (Sum of filling rates) − (Emptying rate)
Rate of the first pipe = 1/6
Rate of the second pipe = 1/8
Rate of the leak = 1/12
Net rate = 1/6 + 1/8 − 1/12
= (4 + 3 − 2) / 24
= 5/24
Time = 24/5 hours
= 4.8 hours
= 4 hours 48 minutes