Ответ:

\[\frac{15}{32}:\frac{5}{8}=\frac{15}{32}\cdot\frac{8}{5}=\frac{3}{4}.\]

\[\frac{3}{4}+\frac{3}{20}=\frac{15}{20}+\frac{3}{20}=\frac{9}{10}.\]

Ответ: \(\frac{9}{10}\).