Q. A pipe can fill a tank in 9 hours and another can empty it in 18 hours. If both are opened together, the tank will be filled in?
✅ Correct Answer: (C)
18 hours
Explanation: Net rate = 1/9 − 1/18 = 1/18.
Explanation by: Kanak Sharma
Net rate = 1/9 − 1/18 = 1/18.