The ratio in which two sugar solutions of the concentrations $15 \%$ and $40 \%$ are to be mixed to get a solution of concentration of $30 \%$ is

$A$ mixture of a certain quantity of milk with $16$ litres of water is worth $90$ $P$ per litre. If pure milk is worth $Rs. 1.08$ per litre,how much milk is there in the mixture? (in Litres)

In what ratio must $25 \%$ hydrochloric acid be mixed with $60 \%$ hydrochloric acid to get a mixture of $40 \%$ hydrochloric acid?

$8$ litres are drawn from a cask full of wine and is then filled with water. This operation is performed three more times. The ratio of the quantity of wine now left in the cask to that of the water is $16$:$65$. How much wine did the cask hold originally? (in litres)

Two vessels contain milk and water in the ratio $3:2$ and $7:3$. Find the ratio in which the contents of the two vessels have to be mixed to get a new mixture in which the ratio of milk and water is $2:1$.

There are $81 \ L$ of pure milk in a container. One-third of the milk is replaced by water. Again,one-third of the mixture is extracted and an equal amount of water is added. What is the ratio of milk to water in the new mixture?