11) 9 7/10 : 3 13/28 =

\(9\dfrac{7}{10}=\dfrac{97}{10},\quad 3\dfrac{13}{28}=\dfrac{97}{28}\)

\(\dfrac{97}{10}:\dfrac{97}{28}=\dfrac{97}{10}\cdot\dfrac{28}{97}=\dfrac{28}{10}=\dfrac{14}{5}=2\dfrac{4}{5}\)

Ответ: \(2\dfrac{4}{5}\)