What will be the duplicate ratio of $2: 7$?

If ₹ $782$ is divided into three parts proportional to $\frac{1}{2}: \frac{2}{3}: \frac{3}{4}$,then the first part is (in ₹):

The mean proportional between $64$ and $81$ is

There are three sections $A, B$ and $C$ in a school of class $I$. The ratio of students in sections $A$ and $B$ is $3:5$ and that in $B$ and $C$ is $4:7$. If the total number of students in the class is $201$,then the number of students in section $A$ is:

$A$ box of sweets was distributed between $A$ and $B$ in the ratio $3:4$. If $A$ got $36$ sweets,what was the total number of sweets?

When $x$ is added to each term of $7: 13$,the ratio becomes $2: 3$. The value of $x$ is