In three vessels,the ratio of water and milk is $6:7$,$5:9$,and $8:7$,respectively. If the mixtures of the three vessels are combined,what will be the final ratio of water to milk?

Three boxes of capacity $24\, kg$,$36\, kg$,and $84\, kg$ are completely filled with three varieties of wheat $A$,$B$,and $C$ respectively. All three boxes were emptied,the three types of wheat were thoroughly mixed,and the mixture was put back into the three boxes. How many $kg$ of type $A$ wheat would be there in the third box?

In what proportion must water be added to spirit to gain $20 \%$ by selling it at the cost price (in $:5$)?

$A$ mixture contains spirit and water in the ratio $3:2$. If it contains $3 \ L$ more spirit than water,the quantity of spirit in the mixture is......$L$.

$A$ shopkeeper has $50 \ kg$ of rice,a part of which he sells at $10 \%$ profit and the rest at $5 \%$ loss. He gains $7 \%$ on the whole. What is the quantity sold at $10 \%$ gain?

An alloy contains copper,zinc and nickel in the ratio of $5: 3: 2$. The quantity of nickel in $kg$ that must be added to $100\, kg$ of this alloy to have the new ratio $5: 3: 3$ is