Multiple choice

If 160 litres of a solution of milk and water has 25% water, then how much water should be added to the solution so that the percentage of milk becomes 60%?

  1. 20 litres

  2. 30 litres

  3. 35 litres

  4. 40 litres
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Initial solution: 160 liters, 25% water (40L), 75% milk (120L). We add x liters of water. New total = 160 + x. Milk remains 120L. We want milk to be 60% of the new total: 120 / (160 + x) = 0.6. 120 = 0.6 * (160 + x) = 96 + 0.6x. 24 = 0.6x. x = 24 / 0.6 = 40 liters.

AI explanation

In the 160 litres of solution, 25% is water, meaning there are 40 litres of water and 120 litres of milk. If adding x litres of water makes milk 60% of the new total, the equation is 120 equals 0.60 multiplied by (160 plus x). Solving this gives 200 equals 160 plus x, which means x is 40 litres.

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