б) $$ \frac{10\frac{10}{11}}{ \frac{21}{22}} \cdot 6\frac{1}{2} = \frac{\frac{10 \cdot 11 + 10}{11}}{\frac{21}{22}} \cdot \frac{6 \cdot 2 + 1}{2} = \frac{\frac{120}{11}}{\frac{21}{22}} \cdot \frac{13}{2} = \frac{120}{11} \cdot \frac{22}{21} \cdot \frac{13}{2} = \frac{120 \cdot 2 \cdot 11 \cdot 13}{11 \cdot 21 \cdot 2} = \frac{120 \cdot 13}{21} = \frac{40 \cdot 13}{7} = \frac{520}{7} = 74 \frac{2}{7} $$
в) $$ 8 : 2\frac{2}{5} : \frac{1\frac{5}{7}}{ \frac{4}{9}} = 8 : \frac{2 \cdot 5 + 2}{5} : \frac{\frac{1 \cdot 7 + 5}{7}}{ \frac{4}{9}} = 8 : \frac{12}{5} : \frac{\frac{12}{7}}{ \frac{4}{9}} = 8 : \frac{12}{5} : ( \frac{12}{7} \cdot \frac{9}{4} ) = 8 : \frac{12}{5} : \frac{3 \cdot 9}{7} = 8 : \frac{12}{5} : \frac{27}{7} = 8 \cdot \frac{5}{12} \cdot \frac{7}{27} = \frac{8 \cdot 5 \cdot 7}{12 \cdot 27} = \frac{2 \cdot 5 \cdot 7}{3 \cdot 27} = \frac{70}{81} $$
Ответ: б) $$74 \frac{2}{7}$$, в) $$\frac{70}{81}$$