3. Вычислите: 1) \(\frac{7}{15}\cdot\frac{4}{25}\); 2) \(6\frac{3}{4}\cdot1\frac{7}{9}\); 3) \(3\frac{1}{5}:2\frac{2}{5}\).

1. \(\frac{7}{15}\cdot\frac{4}{25}=\frac{28}{375}\).
2. \(6\frac{3}{4}\cdot1\frac{7}{9}=\frac{27}{4}\cdot\frac{16}{9}=12\).
3. \(3\frac{1}{5}:2\frac{2}{5}=\frac{16}{5}:\frac{12}{5}=\frac{16}{5}\cdot\frac{5}{12}=\frac{4}{3}=1\frac{1}{3}\).

Ответ: 1) \(\frac{28}{375}\); 2) \(12\); 3) \(1\frac{1}{3}\).