2 2/3 · 1 6/7 =

\(2\frac{2}{3}=\frac{8}{3}\), \(1\frac{6}{7}=\frac{13}{7}\).

\(\frac{8}{3}\cdot\frac{13}{7}=\frac{104}{21}=4\frac{20}{21}\).

Ответ: 4 20/21.