Решение:
\[ \frac{3}{6} + \frac{7}{12} = \frac{3 \times 2}{6 \times 2} + \frac{7}{12} = \frac{6}{12} + \frac{7}{12} \]
\[ \frac{6}{12} + \frac{7}{12} = \frac{6 + 7}{12} = \frac{13}{12} \]
\[ \frac{13}{12} = 1 \frac{1}{12} \]
Ответ: $$\frac{13}{12}$$