[tex]\bf \begin{array}{ccll} laps&km s\\ \cline{1-2}\\ 1&\frac{15}{4}\\[0.8em] \frac{9}{2}&x \end{array}\implies \cfrac{1}{~~\frac{9}{2}~~}=\cfrac{~~\frac{15}{4}~~}{x}\implies \cfrac{2}{9}=\cfrac{15}{4x}\implies 8x=135 \\\\\\ x=\cfrac{135}{8}\implies x=16\frac{7}{8}[/tex]
