Решение:
$$\frac{7}{8} = \frac{7 \cdot 3}{8 \cdot 3} = \frac{21}{24}$$
$$\frac{21}{24} - \frac{5}{24} = \frac{21 - 5}{24} = \frac{16}{24}$$
$$\frac{16}{24} = \frac{16 \div 8}{24 \div 8} = \frac{2}{3}$$
$$\frac{2}{3} \cdot \frac{3}{14} = \frac{2 \cdot 3}{3 \cdot 14} = \frac{6}{42}$$
$$\frac{6}{42} = \frac{6 \div 6}{42 \div 6} = \frac{1}{7}$$
Ответ: \(\frac{1}{7}\)