1) \(\frac{3}{8} : 12\) 2) \(\frac{5}{9} : 15\) 3) \(\frac{8}{24} : 6\) 4) \(6 : \frac{3}{10}\) 5) \(18 : \frac{9}{11}\) 10) \(\frac{25}{30}\)

Решение:

1. \(\frac{3}{8} : 12 = \frac{3}{8 \cdot 12} = \frac{3}{96} = \frac{1}{32}\)

2. \(\frac{5}{9} : 15 = \frac{5}{9 \cdot 15} = \frac{5}{135} = \frac{1}{27}\)

3. \(\frac{8}{24} : 6 = \frac{8}{24 \cdot 6} = \frac{8}{144} = \frac{1}{18}\)

4. \(6 : \frac{3}{10} = 6 \cdot \frac{10}{3} = \frac{60}{3} = 20\)

5. \(18 : \frac{9}{11} = 18 \cdot \frac{11}{9} = \frac{18 \cdot 11}{9} = 2 \cdot 11 = 22\)

10. \(\frac{25}{30} = \frac{5}{6}\)

Ответ: 1) \(\frac{1}{32}\); 2) \(\frac{1}{27}\); 3) \(\frac{1}{18}\); 4) \(20\); 5) \(22\); 10) \(\frac{5}{6}\).