Ц) \( \left[ \left( 12\frac{1}{2} - 2 \right) : \left( \frac{1}{5} - \frac{1}{40} \right) - \left( 2 + 6\frac{2}{3} \right) : \left( 1\frac{5}{6} - 1\frac{2}{3} \right) \right] : 8 \)

Решение:

1. \( 12\frac{1}{2} - 2 = 10\frac{1}{2} = \frac{21}{2} \)
2. \( \frac{1}{5} - \frac{1}{40} = \frac{8}{40} - \frac{1}{40} = \frac{7}{40} \)
3. \( \frac{21}{2} : \frac{7}{40} = \frac{21}{2} \cdot \frac{40}{7} = 3 \cdot 20 = 60 \)
4. \( 2 + 6\frac{2}{3} = 8\frac{2}{3} = \frac{26}{3} \)
5. \( 1\frac{5}{6} - 1\frac{2}{3} = \frac{11}{6} - \frac{5}{3} = \frac{11}{6} - \frac{10}{6} = \frac{1}{6} \)
6. \( \frac{26}{3} : \frac{1}{6} = \frac{26}{3} \cdot 6 = 26 \cdot 2 = 52 \)
7. \( 60 - 52 = 8 \)
8. \( 8 : 8 = 1 \)

Ответ: 1