56 16 8

$$\frac{5}{16} : \frac{6}{8} = \frac{5}{16} \cdot \frac{8}{6} = \frac{5 \cdot 8}{16 \cdot 6} = \frac{5 \cdot 8}{2 \cdot 8 \cdot 6} = \frac{5}{12}$$

Ответ: 5/12