A tank usually fills up in 8 hours, but due to a leak at the bottom, it takes 2 hours longer to fill completely. How long will it take for the leak alone to drain the full tank?

Explanation

The tank fills in 8 hours without a leak, so the filling rate is 1/8 per hour. With the leak, it takes 10 hours, so the effective filling rate is 1/10 per hour. The leak's rate is the difference: (1/8 - 1/10) = 1/40 per hour. Therefore, the leak alone would empty the tank in 40 hours.