6 5 1-3- 7 10

\[1 \frac{6}{7} : 3 \frac{5}{10} = \frac{1 \cdot 7 + 6}{7} : \frac{3 \cdot 10 + 5}{10} = \frac{13}{7} : \frac{35}{10} = \frac{13}{7} \cdot \frac{10}{35} = \frac{130}{245} = \frac{26}{49}\]