Q. A tank has two inlet pipes and one outlet pipe. Inlet pipes fill the tank in 10 and 20 hours, outlet empties in 40 hours. How long will the tank take to fill?
✅ Correct Answer: (B)
10 hours
Explanation: Net rate = 1/10 + 1/20 − 1/40 = 1/10.
Explanation by: Hriday
Net rate = 1/10 + 1/20 − 1/40 = 1/10.