1) $$12\frac{3}{8} + 8\frac{1}{6} = 12\frac{3 \cdot 3}{8 \cdot 3} + 8\frac{1 \cdot 4}{6 \cdot 4} = 12\frac{9}{24} + 8\frac{4}{24} = 20\frac{13}{24}$$
Ответ: $$20\frac{13}{24}$$