There is a milk sample with 50% water in it. If 1/3rd of this milk is added to equal amount of pure milk, then water in the new mixture will fall down to

Correct Option: 25%

Let the volume of the original milk sample be V. Since it contains 50% water: Volume of water = 0.5 V, and Volume of pure milk = 0.5 V. Now, we take 1/3rd of this sample. Volume of this 1/3rd sample = V/3. In this smaller sample, the composition remains identical: Water = 50% of (V/3) = V/6, and Pure milk = 50% of (V/3) = V/6. This sample is added to an equal amount of pure milk. Therefore, the volume of pure milk added is V/3. In the new mixture: Total Volume = (V/3) + (V/3) = 2V/3. Total Water = V/6 (since pure milk contains no water). To find the percentage of water in the new mixture: Water Percentage = (Total Water ÷ Total Volume) × 100 = (V/6 ÷ 2V/3) × 100 = (1/6 × 3/2) × 100 = (3/12) × 100 = 1/4 × 100 = 25%. Thus, the water in the new mixture will fall down to 25%. Hence, the correct option is A.