2. 3 3/4 : (3/8 : 1 3/7) =

2. $$3 \frac{3}{4} : (\frac{3}{8} : 1 \frac{3}{7}) = \frac{15}{4} : (\frac{3}{8} : \frac{10}{7}) = \frac{15}{4} : (\frac{3}{8} \cdot \frac{7}{10}) = \frac{15}{4} : \frac{3 \cdot 7}{8 \cdot 10} = \frac{15}{4} : \frac{21}{80} = \frac{15}{4} \cdot \frac{80}{21} = \frac{15 \cdot 80}{4 \cdot 21} = \frac{5 \cdot 20}{1 \cdot 7} = \frac{100}{7} = 14 \frac{2}{7}$$

Ответ: 14 2/7