CAT 1994 — QA Question 28
There is a leak in the bottom of the tank. This leak can empty a full tank in 8 hours. When the tank is full, a tap is opened into the tank which admits 6 litres per hour and the tank is now emptied in 12 hours. What is the capacity of the tank?
Answer & solution
Correct answer: 144 litres
- A
28.8 litres
- B
36 litres
144 litres
- D
Cannot be determined
Since the leak can empty the tank in 8 hours, the rate of leak = .
And since the leak along with the tap can empty it in 12 hours, the equation can be rewritten as:
(where x is the time taken by the tap to fill the tank).
Simplifying we get, or x = 24.
This means that the tap can fill the tank in 24 hours.
Since the tap admits 6 litres per hour, it will admit (6 × 24) = 144 litres in 24 hours, which should be the capacity of the tank