Question: Pipe A can fill a tank in 6 hours, while pipe B can fill it in 9 hours. If both pipes are opened together, how long will it take to fill the tank?
Options:
Correct Answer: 3 hours
Solution:
The combined rate is 1/6 + 1/9 = 5/18. Therefore, it will take 18/5 = 3.6 hours to fill the tank.