A tank can be filled by an inlet pipe in 8 hours. Another outlet pipe can empty the same tank in 12 hours. If both pipes are opened simultaneously, how long will it take to fill the empty tank completely?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 24 h.
Inlet fills in 8 hr → rate = 1/8
Outlet empties in 12 hr → rate = 1/12
Net work in 1 hour = 1/8 - 1/12 = 1/24
So, time to fill = 24 hours