\[\boxed{\mathbf{116.}}\]
\[\textbf{а)}\]
\[\textbf{б)}\ P(A) = \frac{1}{3} \cdot \frac{1}{2} + \frac{1}{3} \cdot \frac{1}{3} = \frac{1}{6} + \frac{1}{9} =\]
\[= \frac{3}{18} + \frac{2}{18} = \frac{5}{18}.\]
\[\textbf{в)}\ P(B) = \frac{1}{3} + \frac{1}{3} \cdot \frac{1}{3} = \frac{1}{3} + \frac{1}{9} =\]
\[= \frac{3}{9} + \frac{1}{9} = \frac{4}{9}.\]