\[\boxed{\mathbf{222\ (222)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ \frac{16}{63}\ \ + \frac{12}{63} = \frac{28}{63} = \frac{4}{9}\]
\[2)\ \frac{53}{85} - \frac{19}{85} = \frac{34}{85} = \frac{2}{5}\]
\[3)\ 8\frac{34}{81} + 2\frac{38}{81} = 10\frac{72}{81} = 10\frac{8}{9}\]
\[4)\ 3\frac{49}{56} - 3\frac{17}{56} = \frac{32}{56} = \frac{4}{7}\]
\[\boxed{\mathbf{222}\mathbf{.}}\]
\[1)\ 3\ ч;\]
\[2)\ 15\ мин;\]
\[3)\ 15\ с.\]