We know that 1 mile is equal to 1.61 kilometers.
You have to determine how many miles Sarah walked if she walked 5 kilometers. You can use cross multiplication to convert the units:
1.61km =1mile
5km=xmiles
[tex]\begin{gathered} \frac{1}{1.61}=\frac{x}{5} \\ (\frac{1}{1.61})\cdot5=x \\ x=3.105\cong3.11 \end{gathered}[/tex]
She walked 3.11 miles
