To multiply the fractions \( \frac{3}{5} \) and \( \frac{1}{8} \), you multiply the numerators together and the denominators together:
\[ \frac{3}{5} \times \frac{1}{8} = \frac{3 \times 1}{5 \times 8} = \frac{3}{40} \]
So, in the format \(\frac{[?]}{ [?]}\), the answer is:
\[ \frac{3}{40} \]
Thus, the answer is \(\frac{3}{40}\).