keeping in mind that, there are 5280 feet in 1 mile, and 60 minutes in an hour and 60 seconds in each minute, thus 60*60 seconds in an hour, or 3600 seconds.
[tex]\bf \cfrac{76~\underline{feet}}{\underline{sec}}\cdot \cfrac{mile}{5280~\underline{feet}}\cdot \cfrac{3600~\underline{sec}}{hr}\implies \cfrac{76\cdot 3600~mile}{5280~hr}
\\\\\\
\cfrac{570~mile}{11~hr}\approx 51.\overline{81}\frac{mile}{hr}\\\\
-------------------------------\\\\
\textit{how many miles does it do in 3.1hrs?}\quad \cfrac{570}{11}\cdot 3.1[/tex]
