3) 5.28; 14

3) $$\frac{5}{14} \cdot 28 = \frac{5}{14} \cdot \frac{28}{1} = \frac{5 \cdot 28}{14 \cdot 1} = \frac{5 \cdot 2 \cdot 14}{14 \cdot 1} = \frac{5 \cdot 2}{1} = 10$$

Ответ: 10