2 2/5 : 6 6/7 =

$$ 2\frac{2}{5} : 6\frac{6}{7} = \frac{12}{5} : \frac{48}{7} = \frac{12}{5} \cdot \frac{7}{48} = \frac{1}{5} \cdot \frac{7}{4} = \frac{7}{20} $$

Ответ: $$\frac{7}{20}$$