5) 12: 3

5) $$\frac{2}{8} : 2\frac{2}{3} = \frac{2}{8} : \frac{2 \cdot 3 + 2}{3} = \frac{2}{8} : \frac{8}{3} = \frac{2}{8} \cdot \frac{3}{8} = \frac{2 \cdot 3}{8 \cdot 8} = \frac{6}{64} = \frac{3}{32}$$

Ответ: $$\frac{3}{32}$$