A container is full of milk. One-third of milk is taken out of it and replaced by same quantity of water. Then again one-third of the mixture is taken out of it and replaced by the same quantity of water. The process is repeated 4 times. If 16 litres of milk is left in the container at the end of 4th operation, find the capacity of the container.

• A. 76 litres
• B. 85 litres
• C. 82 litres
• D. 81 litres

Answer: (D)

Let capacity of the container be P liter; then P(1 ? 1/3)4 = 16 ? P (2 / 3)4 = 16 ? P(16 / 81) = 16 liters? P = 81 liters