Q. Pipe A fills a tank in 15 hours and pipe B empties it in 20 hours. Pipe C fills it in 30 hours. If all are opened together, how long will it take to fill the tank?
✅ Correct Answer: (B)
60 hours
Explanation: Net rate = 1/15 + 1/30 − 1/20 = 1/60.
Explanation by: Hriday
Net rate = 1/15 + 1/30 − 1/20 = 1/60.