a) \( \left( \frac{7}{8} + \frac{5}{6} \right) \cdot 24 \)

\( \frac{7}{8} + \frac{5}{6} = \frac{21}{24} + \frac{20}{24} = \frac{41}{24} \). \( \frac{41}{24} \cdot 24 = 41 \). Ответ: \(41\).