Let x% of 260 is 312.
x% if 260 can be determined as,
[tex]260\times\frac{x}{100}=\frac{13x}{5}[/tex]Now according to question,
[tex]\begin{gathered} \frac{13x}{5}=312 \\ x=\frac{312\times5}{13} \\ x=120 \end{gathered}[/tex]Thus, 120 percent of 260 is 312.