In order to find the percentage that 13 represents from 25, we can use the following rule of three, knowing that 25 students represent 100%:
[tex]\begin{gathered} 25\text{ students}\to100\text{\%} \\ 13\text{ students}\to x\text{\%} \\ \\ \frac{25}{13}=\frac{100}{x} \\ 25x=13\cdot100 \\ x=\frac{1300}{25} \\ x=52 \end{gathered}[/tex]So 13 students is 52% of 25 students.