Ё) \( \frac{1}{20} + \frac{1}{4} + \frac{2}{5} = \frac{1}{20} + \frac{1 · 5}{4 · 5} + \frac{2 · 4}{5 · 4} = \frac{1}{20} + \frac{5}{20} + \frac{8}{20} = \frac{1+5+8}{20} = \frac{14}{20} = \frac{7}{10} \)