Multiple choice

A container of 108 litre capacity is filled with pure milk. From this 18 litres is taken out and replaced with water. If this process is repeated two more times find the quntity of water in container.

  1. 30 litre

  2. 28.8 litre

  3. 36.5 litre

  4. 45.5 litre

  5. None of these

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

After each operation, milk remaining = Previous × (1 - 18/108) = Previous × (90/108) = Previous × (5/6). After 3 iterations: Milk = 108 × (5/6)³ = 108 × 125/216 = 62.5 L. Water added = Total - Milk = 108 - 62.5 = 45.5 L.