A tank can be filled by pipe A in 10 hours and by pipe B in 15 hours. How long will it take to fill the tank if both pipes are opened together?
Q1. A tank can be filled by pipe A in 10 hours and by pipe B in 15 hours. How long will it take to fill the tank if both pipes are opened together?
Answer: 6 hours
Explanation: The combined rate of filling is 1/10 + 1/15 = 3/30 + 2/30 = 5/30 = 1/6. So, the tank will be filled in 6 hours.