Varun's expenditures and savings are in the ratio of $4:1$. His income increases by $20\%$. If his savings increase by $12\%$, by how much percentage should his expenditure increase?

$A$ and $B$ are two alloys of gold and copper prepared by mixing metals in the ratio $7:2$ and $7:11$ respectively. If equal quantities of the alloys are melted to form a third alloy $C$,the ratio of gold and copper in $C$ will be

In what ratio must water be added to spirit to gain $10 \%$ by selling it at the cost price?

Two vessels $A$ and $B$ contain milk and water mixed in the ratio $8: 5$ and $5: 2,$ respectively. The ratio in which these two mixtures should be mixed to get a new mixture containing $69 \frac{3}{13} \%$ milk is

In a mixture of milk and water with a total volume of $60$ $L$,the ratio of milk to water is $7:5$. How much water must be added to make the ratio of milk to water equal $(1:1)$? (in $L$)

$A$ sum of ₹ $390$ was divided among $450$ boys and girls. Each girl gets $50$ paise and each boy gets one rupee. How many girls are there among them?