③) 1) 1/3 · 2½ = ? 2) 1⅖ · ¼ = ? 3) 1¼ · ⅘ = ?

Решение:

1. 1) \( \frac{1}{3} \cdot 2\frac{1}{2} = \frac{1}{3} \cdot \frac{5}{2} = \frac{5}{6} \)
2. 2) \( 1\frac{2}{5} \cdot \frac{1}{4} = \frac{7}{5} \cdot \frac{1}{4} = \frac{7}{20} \)
3. 3) \( 1\frac{1}{4} \cdot \frac{4}{5} = \frac{5}{4} \cdot \frac{4}{5} = 1 \)

Ответ: 1) \(\frac{5}{6}\); 2) \(\frac{7}{20}\); 3) 1.