$A$ bottle contains $81$ litres of pure milk. $\frac{1}{3}$ of the milk is replaced by the same amount of water. Again,$\frac{1}{3}$ of the mixture is replaced by the same amount of water. The ratio of the milk and water in the new mixture is

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 $g$)

$60\, kg$ of an alloy $A$ is mixed with $100\, kg$ of alloy $B.$ If alloy $A$ has lead and tin in the ratio $3:2$ and alloy $B$ has tin and copper in the ratio $1:4,$ the amount of tin in the new alloy is (in $kg$)

In the first alloy,zinc and copper are in the ratio $1:2.$ In the second alloy,the same elements are in the ratio $2:3.$ If these two alloys are mixed to form a new alloy in which the two elements are in the ratio $5:8,$ the ratio of these two alloys in the new alloy is

$A$ merchant has $1000 \ kg$ of sugar,part of which he sells at $8 \%$ profit and the rest at $18 \%$ profit. If he gains $14 \%$ on the whole,then the quantity sold at $18 \%$ profit is.......$kg$.

In what proportion must sugar of $Rs. 17$ per $kg$ be mixed with sugar of $Rs. 29$ per $kg$ to make a mixture of $Rs. 20$ per $kg$?