A 90-liter mixture contains milk and water in the ratio 8 : 7. If 15 liters of this mixture is taken out and replaced with 15 liters of pure milk, what is the new ratio of milk to water?
Show answer & explanation
Correct answer: C
Explanation
Total mixture = 90 L
Milk : Water = 8 : 7
Mixture removed = 15 L
Added = 15 L of pure milk
According to the formula:
Each component in the mixture = (Ratio / Total Ratio) × Total Quantity
Total Ratio = 8 + 7 = 15
Milk = (8/15) × 90 = 48 L
Water = (7/15) × 90 = 42 L
15 L of mixture was removed
Milk removed = (8/15) × 15 = 8 L
Water removed = (7/15) × 15 = 7 L
Remaining milk = 48 − 8 = 40 L
Remaining water = 42 − 7 = 35 L
Now, 15 L of pure milk was added
New milk = 40 + 15 = 55 L
Water = 35 L
New Ratio = 55 : 35 = 11 : 7