1) 4/7 * 21/32

1) $$ \frac{4}{7} \cdot \frac{21}{32} = \frac{4 \cdot 21}{7 \cdot 32} = \frac{4 \cdot 3 \cdot 7}{7 \cdot 4 \cdot 8} = \frac{3}{8} $$

Ответ: $$\frac{3}{8}$$