\[\boxed{\mathbf{2.}\mathbf{118}}\]
\[\textbf{а)}\ 19\ :5 = \frac{19}{5} = 3\frac{4}{5}\]
\[\textbf{б)}\ 20\ :7 = \frac{20}{7} = 2\frac{6}{7}\]
\[\textbf{в)}\ 21\ :5 = \frac{21}{5} = 4\frac{1}{5}\]
\[\textbf{г)}\ 392\ :16 = \frac{392}{16} = 24\ \frac{8}{16} =\]
\[= 24\frac{1}{2}\]