Calculate the time it will take for a full tank of water to become completely empty due to a leak given that the tank could be filled in 10 hours, but due to the leak in its bottom it takes 11 hours to be filled ?
Choose the correct option
A) 90 hours  B) 80 hours  C) 50 hours  D) 120 hours  E) 110 hours

Rationale: part filled without leak in 1 hour = 1 / 10 part filled with leak in 1 hour = 1 / 11 work done by leak in 1 hour = 1 / 10 â ˆ ’ 1 / 11 = 110 hours answer : e
Answer: E