Each of the questions below consists of a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements and give answer:
A, B, and C are three pipes in a tank. A and B are outlet pipes and C is an inlet pipe. The ratio of the efficiency of A : B is 3 : 1 and that of B : C is 1 : 2. What is the capacity of the tank?
Statement I: If all three pipes are opened, the water in the tank will decrease at the rate of 30 litres per minute.
Statement II: The time taken by C to fill the tank is 60 minutes less than the time taken by B to empty the tank.