1. Сократите дроби: 20/25, 66/72, 120/30.

1. \(\frac{20}{25}=\frac{20:5}{25:5}=\frac45\).
2. \(\frac{66}{72}=\frac{66:6}{72:6}=\frac{11}{12}\).
3. \(\frac{120}{30}=4\).

Ответ: \(\frac45;\ \frac{11}{12};\ 4\).