If $P \%$ of $P$ is $36,$ then $P$ is equal to

If all sides of a hexagon are increased by $7 \%$,find the percentage increase in its area. (in $\%$)

The first and second numbers are less than a third number by $30 \%$ and $37 \%$,respectively. The second number is less than the first by: (in $\%$)

Two numbers are respectively $60 \%$ and $20 \%$ more than a third number. The second number expressed as a percentage of the first is:

There are $1400$ students in the school. $25 \%$ of them wear spectacles and $\frac{2}{7}$ of those who wear spectacles are boys. How many girls in the school wear spectacles?

What percent of $7.2 \,kg$ is $18 \,g$?