\(\dfrac{2}{7}\cdot\dfrac{14}{15}\cdot\dfrac{5}{6}:\dfrac{3}{8}:\dfrac{2020}{2021}\)
\(=\dfrac{2}{7}\cdot\dfrac{14}{15}\cdot\dfrac{5}{6}\cdot\dfrac{8}{3}\cdot\dfrac{2021}{2020}\)
\(=\dfrac{14}{7}\cdot\dfrac{5}{15}\cdot\dfrac{8}{6}\cdot\dfrac{2}{3}\cdot\dfrac{2021}{2020}\)
\(=2\cdot\dfrac{1}{3}\cdot\dfrac{4}{3}\cdot\dfrac{2}{3}\cdot\dfrac{2021}{2020}\)
\(=\dfrac{8084}{13635}\)