Решение:
\[ 3 \frac{2}{5} - 1 \frac{3}{4} = \frac{17}{5} - \frac{7}{4} = \frac{17 \times 4 - 7 \times 5}{20} = \frac{68 - 35}{20} = \frac{33}{20} \]
\[ \frac{33}{20} \cdot 3 \frac{1}{3} = \frac{33}{20} \cdot \frac{10}{3} = \frac{33 \times 10}{20 \times 3} = \frac{11 \times 1}{2 \times 1} = \frac{11}{2} \]
\[ \frac{3}{7} : 3 \frac{3}{7} = \frac{3}{7} : \frac{24}{7} = \frac{3}{7} \cdot \frac{7}{24} = \frac{3 \times 7}{7 \times 24} = \frac{3}{24} = \frac{1}{8} \]
\[ \frac{11}{2} + \frac{1}{8} + \frac{1}{2} = \frac{11 \times 4}{2 \times 4} + \frac{1}{8} + \frac{1 \times 4}{2 \times 4} = \frac{44}{8} + \frac{1}{8} + \frac{4}{8} = \frac{44 + 1 + 4}{8} = \frac{49}{8} \]
\[ \frac{49}{8} = 6.125 \]
Ответ: 6.125