Question: A tank can be filled by two pipes in 12 hours and 15 hours respectively. How long will it take to fill the tank if both pipes are opened together? (2021)
Options:
Correct Answer: 9 hours
Exam Year: 2021
Solution:
Rate of first pipe = 1/12, Rate of second pipe = 1/15. Combined rate = 1/12 + 1/15 = 1/7.2. Time = 7.2 hours.