Multiple choice

A vessel is filled with milk. Three liters of milk is drawn from it and replaced with water. Again 3 liters are drawn and replaced with water. The ratio of milk and water is now found to be 4 : 5. What is the capacity of the vessel in liters? एक पात्र दूध से भरा हुआ है | तीन लीटर दूध निकाला जाता है और पानी से प्रतिस्थापित किया जाता है | पुनः 3 लीटर निकाला जाता है और पानी से प्रतिस्थापित किया जाता है। अब दूध और पानी का अनुपात 4 : 5 प्राप्त किया जाता है | पात्र की क्षमता लीटर में क्या है?

  1. 9

  2. 12

  3. 3

  4. 5

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let capacity = x liters. After first replacement: milk = x-3. After second: milk = (x-3)²/x. Final milk ratio = 4/9, so (x-3)²/x² = 4/9. Solving: 3(x-3) = 2x, giving x = 9. Verification: after two operations, milk fraction = (6/9)² = 36/81 = 4/9 ✓