Multiple choice

A mixture of 72 litre of milk and water contains 10% of water. How much water must be added to make 20% water in the new mixture?

  1. 7 ltr

  2. 8 ltr

  3. 9 ltr

  4. 5 ltr

  5. 12 ltr
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Initial mixture: 72 L with 10% water = 7.2 L water, 64.8 L milk. Let x be water added. New mixture: (7.2 + x) water in (72 + x) total = 20%. Solving: (7.2 + x) = 0.2(72 + x), giving 7.2 + x = 14.4 + 0.2x, so 0.8x = 7.2, x = 9 liters.

Keep practicing — related questions