\[\frac{k - 2p}{p} = 3\]
\[\frac{k}{p} - \frac{2p}{p} = 3\]
\[\frac{k}{p} - 2 = 3\]
\[\frac{k}{p} = 3 + 2 = 5\]
\[\frac{p}{k} = \frac{1}{5}.\]