Ravi is $12$ years younger than Surya. Ravi's age is $40 \%$ of the sum of his and Surya's age. What will be Surya's age $9$ years hence?

Number of appeared candidates from State $Q$ increased by $100 \%$ from $2006$ to $2007$. If the total number of qualified candidates from State $Q$ in $2006$ and $2007$ together is $408$,what is the number of appeared candidates from State $Q$ in $2006$?

The population of a town $2$ years ago was $62500$. Due to migration to big cities,it decreases every year at the rate of $4\%$. The present population of the town is:

If $35 \%$ of $A$'s income is equal to $25 \%$ of $B$'s income,then the ratio of $A$'s income to $B$'s income is

In a school there are $1500$ students,$44 \%$ of whom are girls. The monthly fee of each boy is $₹ 540$ and the fee of each girl is $25 \%$ less than that of a boy. What is the sum of the monthly fees of all the boys and girls?

Two numbers $A$ and $B$ are such that the sum of $6\%$ of $A$ and $4\%$ of $B$ is two-thirds of the sum of $6\%$ of $A$ and $8\%$ of $B$. Find the ratio of $A:B$.