Answer :

[tex]6 \frac{1}{2}mi.......2h \\\\ 16\frac{1}{4}mi........x \\\\ \hbox{Introduce the units in the fractions} \\\\\\ \frac{13}{2}mi.........2h \\\\ \frac{65}{4}mi.........x \\\\ \hbox{Solve the proportion obtained:} \\\\ x= \frac{\frac{65}{\not4}\not mi*\not2h}{\frac{13}{2}\not mi} \\\\ \hbox{Simplify the units of measurement and 4 with 2 } \\\\\\ x=\frac{\frac{65}{2}h}{\frac{13}{2}} \\\\ x= \frac{\not65}{\not2}h* \frac{\not2}{\not13} \\\\ \hbox{Simplify 65 and 13 throw 13 and 2 with 2} \\\\ \boxed{x=5 \ hours}[/tex]