TeX source:

\begin{gathered} \frac{\text { distance }}{\text { time }}=\frac{80 \text { miles }}{105 \text { minutes }} \\ \\ \frac{80 \text { miles }}{105 \text { minutes }} \times \frac{5280 \text { feet }}{1 \text { mile }} \times \frac{1 \text { meter }}{3.28 \text { feet }} \times \frac{1 \text { minute }}{60 \text { seconds }}=20 \mathrm{~m} / \mathrm{s} \end{gathered}