Question

From a container, 6 litres milk was drawn out and was replaced by water. Again 6 litres of mixture was drawn out & was replaced by the water. Thus the quantity of milk and water in the container after these two operations is 9 :16. The quantity of mixture is :

• A. 15
• B. 16
• C. 25
• D. 31

Answer 1

The correct option is A 15

$\begin{array}{ccc}& \frac{9}{25}={(1-\frac{6}{K})}^2\Rightarrow & \frac{3}{5}=(1-\frac{6}{K})\\ \Rightarrow & K=15litre& \end{array}$