Multiple choice

In mixture of 40 litres of milk and water contains 10% water. How much water must be added to make water 20% in the new mixture? 40 लीटर दूध और पानी के मिश्रण में 10% पानी है। मिश्रण में पानी की मात्रा क्या मिला दी जाये कि पानी की मात्रा 20% हो जाये?

  1. 6 litres 6 लीटर

  2. 8 litres 8 लीटर

  3. 10 litres 10 लीटर

  4. 5 litres 5 लीटर

  5. None of these इनमें से कोई नहीं
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In 40 litres, water is 10%, so water = 4 litres, milk = 36 litres. Let x litres of water be added. New water = 4 + x, new total = 40 + x. We want (4 + x) / (40 + x) = 20% = 0.2. So 4 + x = 0.2(40 + x) = 8 + 0.2x. Therefore x - 0.2x = 8 - 4, so 0.8x = 4, giving x = 5 litres.

Keep practicing — related questions