B) \(\frac{15}{16} : \frac{3}{8} \cdot \frac{3}{4}\)

Решение:

1. \( \frac{15}{16} : \frac{3}{8} = \frac{15}{16} \cdot \frac{8}{3} = \frac{\cancel{15}^5 \cdot \cancel{8}^1}{\cancel{16}^2 \cdot \cancel{3}^1} = \frac{5 \cdot 1}{2 \cdot 1} = \frac{5}{2} \)
2. \( \frac{5}{2} \cdot \frac{3}{4} = \frac{5 \cdot 3}{2 \cdot 4} = \frac{15}{8} \)

Ответ: \( \frac{15}{8} \)