11) \(\frac{7}{8}\cdot\frac{4}{5}:\frac{1}{2}+\frac{3}{10}\)

\(\frac{7}{8}\cdot\frac{4}{5}=\frac{7}{10}\).

\(\frac{7}{10}:\frac{1}{2}=\frac{7}{10}\cdot2=\frac{7}{5}\).

\(\frac{7}{5}+\frac{3}{10}=\frac{14}{10}+\frac{3}{10}=\frac{17}{10}\).

Ответ: \(\frac{17}{10}\)