Three glasses of capacity $2 \, L$,$5 \, L$,and $9 \, L$ contain mixtures of milk and water with milk concentrations of $90 \%$,$80 \%$,and $70 \%$ respectively. The contents of the three glasses are emptied into a large vessel. Find the ratio of milk to water in the resultant mixture.

Three containers whose volumes are in the ratio of $2:3:4$ are full of a mixture of spirit and water. In the $1^{st}$ container,the ratio of spirit to water is $4:1$,in the $2^{nd}$ container the ratio is $11:4$,and in the $3^{rd}$ container the ratio is $7:3$. All three mixtures are mixed in a big container. The ratio of spirit and water in the resultant mixture is:

$600 \, gm$ of sugar solution contains $40 \%$ sugar. How much sugar should be added to make the concentration $50 \%$ in the solution? (in $gm$)

In a $729 \ L$ mixture of milk and water,the ratio of milk to water is $7:2.$ To get a new mixture containing milk and water in the ratio $7:3,$ the amount of water to be added is (in $L$)

In what ratio must water be mixed with milk to gain $16 \frac{2}{3} \%$ on selling the mixture at cost price?

In what ratio should two varieties of tea,one costing ₹$25$ per $kg$ and the other costing ₹$30$ per $kg$,be blended to produce a blended variety of tea worth ₹$28$ per $kg$?