Решение:

a) $$3\frac{1}{5} \cdot 3\frac{1}{8} = \frac{16}{5} \cdot \frac{25}{8} = \frac{2 \cdot 5}{1 \cdot 1} = 10$$

б) $$1\frac{4}{11}:1\frac{2}{13} = \frac{15}{11} : \frac{15}{13} = \frac{15}{11} \cdot \frac{13}{15} = \frac{13}{11} = 1\frac{2}{11}$$

в) $$2\frac{3}{4}:1\frac{3}{8} \cdot 3\frac{2}{7} = \frac{11}{4} : \frac{11}{8} \cdot \frac{23}{7} = \frac{11}{4} \cdot \frac{8}{11} \cdot \frac{23}{7} = \frac{2}{1} \cdot \frac{23}{7} = \frac{46}{7} = 6\frac{4}{7}$$

Ответ:

а) $$10$$

б) $$1\frac{2}{11}$$

в) $$6\frac{4}{7}$$