Multiple choice

In a 30 litre mixture of water and milk there is 90% milk. What amount of water should be mixed in the mixture so that milk content became 80%?

  1. 2.75 litre

  2. 3 litre

  3. 3.75 litre

  4. 5.65 litre

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Initial mixture: 30L total, 90% milk = 27L milk and 3L water. After adding x liters of water, total volume = (30+x) liters. Milk percentage = 27/(30+x) = 80% = 0.8. Solving: 27 = 0.8(30+x) → 27 = 24 + 0.8x → 0.8x = 3 → x = 3.75 liters. Option C is correct.

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