Solution:
Given that Lang walks
[tex]\frac{2}{3}[/tex]of a mile each day, this implies that
[tex]1\text{ day }\Rightarrow\text{ }\frac{2}{3}\text{ mile}[/tex]Thus, in order to evaluate how many days she has to walk a whole number of miles, we multiply through by 3.
Thus,
[tex]\begin{gathered} 3(1\text{ day) }\Rightarrow3(\text{ }\frac{2}{3}\text{ mile)} \\ \text{thus, we have} \\ 3\text{ days }\Rightarrow\text{ 2 miles} \end{gathered}[/tex]This implies that in order to walk a whole number of miles, she has to walk 3 days.