What percentage of $12.5$ is $39$?

Hint: We will begin by assuming that x percent of 64 is equal to 8. Make a mathematical representation of this in the form of an equation. The equation's left-hand side is $x$ divided by 100 multiplied by 64, and the equation's right-hand side is 8. Calculate the value of $x$, which is your answer, by solving the equation.

Complete step by step answer:
We will begin our answer to the preceding issue by assuming that x percent of 64 equals 8.
We will now represent it formally as an equation. The equation's left-hand side is x divided by 100, and the result is multiplied by 64, while the right-hand side is 8.
$ \Rightarrow \dfrac{x}{{100}} \times 12.5 = 39$
We will multiply both side by 100, we get
$ \Rightarrow x \times 12.5 = 39 \times 100$
We will divide both side by 12.5, we get
$ \Rightarrow x = \dfrac{{39 \times 100}}{{12.5}}$
When we solve RHS , we get
$ \therefore x = 312\% $

Hence, the 312 percentage of 12.5 is 39.

Note: If one faces a problem in interpreting percentage related problems. We can convert the $x\% $ of y units, replace $\% $ sign by $\dfrac{1}{{100}}$ , ‘of’ by multiplication sign. So, the mathematical representation is $\left( {\dfrac{x}{{100}} \times y} \right)\,units$.