Multiple choice

A 60-liter mixture contains milk and water in the ratio 7 : 3. How much milk must be added to make the ratio 4 : 1?

  1. 20

  2. 30

  3. 45

  4. 60

  5. 80
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Initial mixture: 60 liters, ratio 7:3 (42L milk, 18L water). Let x be the amount of milk added. New ratio: (42+x)/18 = 4/1. Solving for x: 42 + x = 72, so x = 30.

AI explanation

The original 60-liter mixture contains milk and water in a 7:3 ratio, yielding 42 liters of milk and 18 liters of water. To achieve a 4:1 ratio by adding only milk, the 18 liters of water must represent 1 part of the new total, meaning the new milk quantity must be 4 parts, or 72 liters. The difference between the new and old milk quantities is 72 minus 42, which equals 30 liters of milk to be added.

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