A cistern is normally filled in 6 hrs,but takes 2 hrs longer to fill because of a leak on its bottom,if Cistern is full ,how much time citern would empty? Choose the most appropriate option
A) 24 hours B) 20 hours C) 30 hours D) 40 hours E) 50 hours

Rationale: "if leakage / hour = 1 / x , then 1 / 6 - 1 / x = 1 / 8 , solving 1 / x = 1 / 24 so in 24 hours full cistern will be empty . answer : a"
Answer: A