A container of 63 liters was full of milk. 09 liters liquid was drawn off and replaced by water and further 07 liters liquid drawn off and replaced by water. Find quantity of water in the mixture now.

15 liters

Ratio of milk and water in original mixture = 63 : 0

After the first exchange, this ratio becomes

Milk : Water = 54 : 9 = 6 : 1

In the secong exchange,

quanity of water in the 7 litres of mixtures drawn

= 7 x \(\frac{1}{7}\) = 1

Thus, the final quantity of water = 9 - 1 + 7 = 15