Решение:
\[ \frac{2}{5} + \frac{1}{10} = \frac{2 \times 2}{5 \times 2} + \frac{1}{10} = \frac{4}{10} + \frac{1}{10} \]
\[ \frac{4}{10} + \frac{1}{10} = \frac{4 + 1}{10} = \frac{5}{10} \]
\[ \frac{5}{10} = \frac{5 \div 5}{10 \div 5} = \frac{1}{2} \]
Ответ: $$\frac{1}{2}$$