\[\boxed{\mathbf{255.}}\]
\[\textbf{а)}\ \frac{1}{2} \cdot \frac{1}{2} \cdot \frac{1}{2} = \frac{1}{8}.\]
\[\textbf{б)}\ \frac{1}{2} \cdot \frac{1}{2} \cdot \frac{1}{2} \cdot \frac{1}{2} = \frac{1}{16}.\]
\[\textbf{в)}\ \frac{1}{2^{10}} = \frac{1}{1024}.\]