[tex]\bf m=\cfrac{rise}{run}\implies \cfrac{\quad \frac{3}{8}~mile\quad }{\frac{3}{5}~hour}
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m=\cfrac{\quad \frac{3}{8}\quad }{\frac{3}{5}}\implies m=\cfrac{\underline{3}}{8}\cdot \cfrac{5}{\underline{3}}\implies m=\cfrac{5~miles}{8~hour}\implies m=0.625~\frac{miles}{hour}[/tex]