A 30-litre container of pure milk undergoes a 6-litre removal and 6-litre water replacement process, repeated 4 times. Approximately how much original milk remains?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 12 litres.
Initial milk = 30 L
Each operation: Remove 6 L mixture → Milk part left = (30 - 6)/30 = 24/30 = 4/5
After 4 operations:
Milk = 30 × (4/5)4 = 30 × 256/625 = 12.288 ≈ L