Calculate the time it will take for a full tank to become completely empty due to a leak given that
the tank could be filled in 7 hours, but due to the leak in its bottom it takes 8 hours to be filled ? Choices.
A) 59 hours
B) 54 hours
C) 59 hours
D) 56 hours
E) 26 hours

Rationale: part filled without leak in 1 hour = 1 / 7 part filled with leak in 1 hour = 1 / 8 work done by leak in 1 hour = 1 / 7 â ˆ ’ 1 / 8 = 56 hours answer : d
Answer: D