$$\frac{11}{14} : 2\frac{1}{7} \cdot \frac{12}{35} = $$
$$\frac{11}{14} : \frac{15}{7} \cdot \frac{12}{35} = $$
$$\frac{11}{14} \cdot \frac{7}{15} \cdot \frac{12}{35} = $$
$$\frac{11}{2} \cdot \frac{1}{15} \cdot \frac{12}{35} = $$
$$\frac{11}{1} \cdot \frac{1}{5} \cdot \frac{4}{35} = $$
$$\frac{44}{175}$$
Ответ: $$\frac{44}{175}$$