Question

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

• A. 12 ltr
• B. 15 ltr
• C. 9 ltr
• D. 6 ltr
• E. 18 ltr

Answer 1

The correct option is B 15 ltr

After these two transfers = milk is left in the container in ratio 9: 25

$\frac{(k-6{)}^2}{k^2}=\frac{9}{25k}=15.$

Hence option (b)