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?

The ratio of milk and water in mixtures of four containers are $5:3, 2:1, 3:2$ and $7:4$ respectively. In which container is the quantity of milk,relative to water,minimum?

In $50\, g$ alloy of gold and silver,the gold is $80\%$ by weight. How much gold should be mixed to this alloy,so that the weight of gold would become $95\%$? (in $g$)

$100$ $litres$ of a mixture contains $20 \%$ water and the rest is milk. The amount of milk that must be added so that the resulting mixture contains $87.5 \%$ milk is (in $litres$):

$A$ can contains a mixture of two liquids $A$ and $B$ in the ratio $7:5$. When $9\,L$ of mixture is drained off and the can is filled with $B$,the ratio of $A$ and $B$ becomes $7:9$. How many litres of liquid $A$ was contained by the can initially?

$8$ 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)