$A$ merchant mixes three varieties of rice costing $Rs. 20$ per $kg$,$Rs. 24$ per $kg$,and $Rs. 30$ per $kg$ and sells the mixture at a profit of $20\%$ at $Rs. 30$ per $kg$. How many $kgs$ of the second variety will be in the mixture if $2$ $kgs$ of the third variety is there in the mixture?

Solution $A$ contains $10 \%$ acid and solution $B$ contains $30 \%$ acid. In what ratio should solution $A$ be mixed with solution $B$ to obtain a mixture with $25 \%$ acid?

If $2 \, kg$ of metal,of which $\frac{1}{3}$ is zinc and the rest is copper,is mixed with $3 \, kg$ of metal,of which $\frac{1}{4}$ is zinc and the rest is copper,what is the ratio of zinc to copper in the mixture?

$A$ 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)

Nine litres of water are drawn from a container full of water and it is then filled with milk. Nine litres of mixture are drawn and the container is again filled with milk. The ratio of the quantity of water now left in the container to that of the milk in it is $16:9$. How much liquid does the container hold? (in $litres$)

$A$ can contains a mixture of two liquids $A$ and $B$ in the ratio $4:7$. When $6 \text{ litres}$ of the mixture are drawn off and the can is filled with liquid $B$,the ratio of $A$ and $B$ becomes $3:7$. How many litres of liquid $A$ were contained in the can initially?