28. Сравните обыкновенные дроби: 1) 5/8 и 2/5; 2) 1/6 и 5/12; 3) 8/12 и 4/9; 4) 11/15 и 4/10; 5) 3/8 и 7/12; 6) 10/13 и 2/3.

1. \(\frac{5}{8}=\frac{25}{40}\), \(\frac{2}{5}=\frac{16}{40}\), поэтому \(\frac{5}{8}>\frac{2}{5}\).
2. \(\frac{1}{6}=\frac{2}{12}<\frac{5}{12}\).
3. \(\frac{8}{12}=\frac{2}{3}=\frac{6}{9}>\frac{4}{9}\).
4. \(\frac{11}{15}=\frac{22}{30}>\frac{12}{30}=\frac{4}{10}\).
5. \(\frac{3}{8}=\frac{9}{24}<\frac{14}{24}=\frac{7}{12}\).
6. \(\frac{10}{13}>\frac{2}{3}\), так как \(30>26\).

Ответ: 1) >; 2) <; 3) >; 4) >; 5) <; 6) >.