there are 60 seconds in 1 minute and 60 minutes in 1 hour.
and there are 1.609km in 1 mile, so, let's use those ratios.
[tex]\bf \cfrac{694~\underline{mile}}{\underline{sec}}\cdot \cfrac{60~\underline{sec}}{\underline{min}}\cdot \cfrac{60~\underline{min}}{hr}\cdot \cfrac{1.609~km}{\underline{mile}}\implies \cfrac{694\cdot 60\cdot 60\cdot 1.609~km}{hr}[/tex]
and I'm sure you know how much that is, since is just a product.
