б) $$1\frac{2}{13} \cdot 1\frac{5}{8} \cdot 1\frac{1}{7} = \frac{1 \cdot 13 + 2}{13} \cdot \frac{1 \cdot 8 + 5}{8} \cdot \frac{1 \cdot 7 + 1}{7} = \frac{15}{13} \cdot \frac{13}{8} \cdot \frac{8}{7} = \frac{15 \cdot 13 \cdot 8}{13 \cdot 8 \cdot 7} = \frac{15}{7} = 2\frac{1}{7}$$
Ответ: $$2\frac{1}{7}$$