[tex]\bf \frac{2}{5}:\frac{1}{15}\implies \cfrac{~~\frac{2}{5}~~}{\frac{1}{15}}\implies \cfrac{2}{~~\begin{matrix} 5 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}\cdot \cfrac{\stackrel{3}{~~\begin{matrix} 15 \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~}}{1}\implies \cfrac{6}{1}\implies 6[/tex]
