A problem by Ewerton Cassiano

$\frac{\theta{F} -32}{9}$ = $\frac{\theta{C}}{5}$ is the formula to convert $\theta{F}$ in $\theta{C}$ , but the question asks in Kelvin or $\theta{K}$ , which formula is $\theta{K}$ = $\theta{C}$ + $273$ ; So, replacing: $\frac{104 -32}{9}$ = $\frac{\theta{C}}{5}$ ;
$\frac{72}{9}$ = $\frac{\theta{C}}{5}$ ; $8$ = $\frac{\theta{C}}{9}$ ; $\theta{C}$ = $40$ ;

But, the question wants in Kelvin. So: $\theta{K}$ = $\theta{C}$ + $273$ = $\theta{K}$ = $40$ + $273$ = $\boxed{313}$