Ответ:
\[\frac{4}{5}+\frac{8}{15}=\frac{12}{15}+\frac{8}{15}=\frac{20}{15}=\frac{4}{3}.\]
\[\frac{3}{16}\cdot\frac{4}{3}=\frac{1}{4}.\]
Ответ: \(\frac{1}{4}\).
\[\frac{4}{5}+\frac{8}{15}=\frac{12}{15}+\frac{8}{15}=\frac{20}{15}=\frac{4}{3}.\]
\[\frac{3}{16}\cdot\frac{4}{3}=\frac{1}{4}.\]
Ответ: \(\frac{1}{4}\).