A water tank is 2/5th full pipe A can fill the tank in 10 minutes and the pipe B can empty it in 6 minutes. If both the pipes are open, how long will it take to empty or fill the tank completely?
Correct Answer: 6 minutes to empty
Explanation:
Time taken to fill or empty the whole tank = (6 x 10) /(6 - 10) = - 15 minutes
- ve sign shows that the tank will be emptied. ∴ 2/5th full of the tank will be emptied in 15 x 2/5 = 6 minutes
