15) 3 3/5 : 1 5/35

\(3\frac{3}{5}:1\frac{5}{35}=\frac{18}{5}:\frac{12}{7}=\frac{18}{5}\cdot\frac{7}{12}=\frac{21}{10}=2\frac{1}{10}\).

Ответ: \(2\frac{1}{10}\).