\[\boxed{\text{5.301.}}\]
\[\textbf{а)}\ 6 + 8\frac{7}{13} = 14\frac{7}{13}\ \]
\[\textbf{б)}\ 12 + 19\frac{5}{24} = 31\frac{5}{24}\ \]
\[\textbf{в)}\ 5\frac{7}{15} + 8\frac{4}{15} = 13\frac{11}{15}\ \]
\[\textbf{г)}\ 13\frac{5}{101} + 7\frac{25}{101} = 20\frac{30}{101}\ \]
\[\textbf{д)}\ 4\frac{3}{7} + 15\frac{4}{7} = 19\frac{7}{7} = 19 + \frac{7}{7} =\]
\[= 19 + 1 = 20\ \]
\[\textbf{е)}\ 3\frac{9}{13} + 4\frac{8}{13} = 7\frac{17}{13} =\]
\[= 7 + \frac{17}{13} = 7 + 1\frac{4}{13} = 8\frac{4}{13}\ \]