A container has 72 litre of pure milk. One–third of the milk is replaced by water in the container. Again, one–third of the mixture is extracted and an equal amount of water is added. What is the ratio of milk to water in the new mixture?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e 4 : 5.
Initial milk (Total) = 72 litres (pure milk) and Remove one-third of 72 = 24 litres of milk
Now
Milk = 72 - 24 = 48 litres and Water = 24 litres
Mixture after second replacement = 48 milk + 24 water = 72 litres
Remove one-third again = 24 litres of mixture
Milk removed = (48/72) × 24 = 16 litres and Water removed = (24/72) × 24 = 8 litres
Remaining Milk = 48 - 16 = 32 litres and Water = 24 - 8 = 16 litres
Add 24 litres of water again
Final mixture:
Milk = 32 litres and Water = 16 + 24 = 40 litres
Final Ratio (Milk : Water) = 32 : 40 = 4 : 5