[tex]\begin{array}{ccll} miles&hours\\ \cline{1-2} 27 & 3\\ x& \frac{1}{2} \end{array} \implies \cfrac{27}{x}=\cfrac{3}{~~ \frac{1}{2}~~}\implies \cfrac{27}{x}=6 \\\\\\ 27=6x\implies \cfrac{27}{6}=x\implies \cfrac{9}{2}=x\implies 4\frac{1}{2}=x[/tex]
