A mixture contains milk and water in the ratio 7:5. How much water must be added to 10 liters of the mixture to make the ratio 9:7?
Show answer & explanation
Correct answer: D
Explanation
Given:
Milk : Water = 7 : 5, Total mixture = 10 liters
According to the formula:
Quantity = Ratio × k
Milk = (7/12) × 10 = 35/6
Water = (5/12) × 10 = 25/6
Let's assume x liters of water are added.
New ratio = 35/6 : (25/6 + x) = 9 : 7
35 / (25 + 6x) = 9 / 7
245 = 225 + 54x
20 = 54x
x = 10/27
10/27 liters of water must be added.