We are given \( 0.375 \). First, convert \( 0.375 \) to a fraction:
\[
0.375 = \frac{375}{1000} = \frac{3}{8}.
\]
Now express \( \frac{3}{8} \) in terms of its prime factors:
\[
\frac{3}{8} = \frac{3}{2^3}.
\]
Thus, the form of \( q \) is \( 2^3 \times 5^2 \).
Therefore, the form of \( q \) is \( \boxed{2^3 \times 5^2} \).