\[\boxed{\mathbf{2.}\mathbf{178}}\]
\[\textbf{а)}\ \frac{1}{6} + \frac{3}{16} + \frac{5}{6} + \frac{5}{16} =\]
\[= \left( \frac{1}{6} + \frac{5}{6} \right) + \left( \frac{3}{16} + \frac{5}{16} \right) =\]
\[= \frac{6}{6} + \frac{8}{16} =\]
\[= 1 + \frac{1}{2} = 1 + 0,5 = 1,5\]
\[\textbf{б)}\ \frac{5}{11} + \frac{2}{3} + \frac{1}{9} + \frac{6}{11} =\]
\[= \left( \frac{5}{11} + \frac{6}{11} \right) + \left( \frac{2^{\backslash 3}}{3} + \frac{1}{9} \right) =\]
\[= \frac{11}{11} + \left( \frac{6}{9} + \frac{1}{9} \right) = 1 + \frac{7}{9} = 1\frac{7}{9}\]