Question

A container is filled with liquid, 6 part of which are water and 10 part milk. How much of the mixture must be drawn off and replaced with water, so that the mixture may be half water and half milk?

Accepted Answer

C. Let the total volume of the mixture be 16 units (6 water, 10 milk). Suppose a fraction $x$ of the mixture is drawn off. Milk removed $= 10x$. Remaining milk $= 10(1 - x)$. In the final mixture, milk should be half of the total volume, i.e., 8 units. $$10(1 - x) = 8 \implies 1 - x = \frac{4}{5} \implies x = \frac{1}{5}$$

Mixture Replacement

Explanation

Practise this under exam conditions