\[\boxed{\text{5.219.}}\]
\[\textbf{а)}\ (64 + 96)\ :16 =\]
\[= 64\ :16 + 96\ :16 = 4 + 6 =\]
\[= 10\]
\[\textbf{б)}\ (3363 + 666)\ :3 =\]
\[= 3363\ :3 + 666\ :3 =\]
\[= 1121 + 222 = 1343\]
\[\textbf{в)}\ 175\ :26 + 137\ :26 =\]
\[= (175 + 137)\ :26 =\]
\[= 312\ :26 = 12\ \]
\[\textbf{г)}\ 2731\ :17 + 669\ :17 =\]
\[= (2731 + 669)\ :17 =\]
\[= 3400\ :17 = 200\ \]