Решение:

а) $$\frac{1-\frac{1}{5}}{2} = \frac{\frac{5}{5}-\frac{1}{5}}{2} = \frac{\frac{4}{5}}{2} = \frac{4}{5} : 2 = \frac{4}{5} \cdot \frac{1}{2} = \frac{4}{10} = \frac{2}{5}$$

Ответ: $$\frac{2}{5}$$

б) $$\frac{6}{1-\frac{1}{3}} = \frac{6}{\frac{3}{3}-\frac{1}{3}} = \frac{6}{\frac{2}{3}} = 6 : \frac{2}{3} = 6 \cdot \frac{3}{2} = \frac{18}{2} = 9$$

Ответ: $$9$$

в) $$\frac{\frac{2}{3}+\frac{1}{6}}{3} = \frac{\frac{4}{6}+\frac{1}{6}}{3} = \frac{\frac{5}{6}}{3} = \frac{5}{6} : 3 = \frac{5}{6} \cdot \frac{1}{3} = \frac{5}{18}$$

Ответ: $$\frac{5}{18}$$

г) $$\frac{1-\frac{1}{6}}{2+\frac{1}{6}} = \frac{\frac{6}{6}-\frac{1}{6}}{\frac{12}{6}+\frac{1}{6}} = \frac{\frac{5}{6}}{\frac{13}{6}} = \frac{5}{6} : \frac{13}{6} = \frac{5}{6} \cdot \frac{6}{13} = \frac{5}{13}$$

Ответ: $$\frac{5}{13}$$

д) $$\frac{\frac{17}{100}-\frac{1}{10}}{10} = \frac{\frac{17}{100}-\frac{10}{100}}{10} = \frac{\frac{7}{100}}{10} = \frac{7}{100} : 10 = \frac{7}{100} \cdot \frac{1}{10} = \frac{7}{1000}$$

Ответ: $$\frac{7}{1000}$$

е) $$\frac{\frac{1}{4}+\frac{2}{3}}{2-\frac{1}{6}} = \frac{\frac{3}{12}+\frac{8}{12}}{\frac{12}{6}-\frac{1}{6}} = \frac{\frac{11}{12}}{\frac{11}{6}} = \frac{11}{12} : \frac{11}{6} = \frac{11}{12} \cdot \frac{6}{11} = \frac{1}{2}$$

Ответ: $$\frac{1}{2}$$