One tap can fill a cistern in 2 hours and another can empty the cistern in 3 hours. How long will they take to fill the cistern if both the taps are opened ?
5 hours
6 hours
7 hours
8 hours
Correct Option: B
Net filling in 1 hour = (1/2 - 1/3) = 1/6 ∴ Time taken to fill the cistern = 6 hours
