Решение:

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

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

B) $$2\frac{3}{8}:1\frac{3}{7}\cdot 3\frac{2}{7} = \frac{19}{8} : \frac{10}{7} \cdot \frac{23}{7} = \frac{19}{8} \cdot \frac{7}{10} \cdot \frac{23}{7} = \frac{19}{8} \cdot \frac{1}{10} \cdot \frac{23}{1} = \frac{437}{80} = 5\frac{37}{80}$$

Ответ:

a) $$10$$

б) $$1\frac{2}{11}$$

B) $$5\frac{37}{80}$$