б) \(\left(\frac{5}{24}+\frac{5}{16}\right)\cdot\left(1\frac{2}{3}-\frac{3}{5}\right)\cdot1\frac{4}{5}=\)

Преобразуем смешанные числа:

\(1\frac{2}{3}=\frac{5}{3}\), \(1\frac{4}{5}=\frac{9}{5}\).

\[\left(\frac{5}{24}+\frac{5}{16}\right)\cdot\left(\frac{5}{3}-\frac{3}{5}\right)\cdot\frac{9}{5}\]

\[=\left(\frac{10}{48}+\frac{15}{48}\right)\cdot\left(\frac{25}{15}-\frac{9}{15}\right)\cdot\frac{9}{5}\]

\[=\frac{25}{48}\cdot\frac{16}{15}\cdot\frac{9}{5}=1.\]

Ответ: \(1\).