\[\boxed{\mathbf{2.}\mathbf{181}}\]
\[c = 1:\]
\[\frac{8 \cdot 1}{75} = \frac{8}{75}.\]
\[c = 3:\]
\[\frac{8 \cdot 3}{75} = \frac{8}{25}.\]
\[c = 6:\]
\[\frac{8 \cdot 6}{75} = \frac{8 \cdot 2}{25} = \frac{16}{25}.\]
\[c = 8:\]
\[\frac{8 \cdot 8}{75} = \frac{64}{75}.\]