Question: If 5 liters of a mixture of milk and water contains 60% milk, how much water must be added to make the mixture 40% milk?
Options:
Correct Answer: 4 liters
Solution:
Initial milk = 60% of 5L = 3L. Let x be the liters of water added. New total = 5 + x. We need 3/(5+x) = 0.4. Solving gives x = 4L.