B) 2\(\frac{1}{8}\) + 3\(\frac{5}{12}\);

2\(\frac{1}{8}\) + 3\(\frac{5}{12}\) = (2+3) + (\(\frac{1}{8}\) + \(\frac{5}{12}\)) = 5 + (\(\frac{1 \cdot 3}{8 \cdot 3}\) + \(\frac{5 \cdot 2}{12 \cdot 2}\)) = 5 + \(\frac{3}{24}\) + \(\frac{10}{24}\) = 5 + \(\frac{13}{24}\) = 5\(\frac{13}{24}\)

Ответ: 5\(\frac{13}{24}\)