Ответ:

\(\frac{5}{12}+\frac{11}{20}=\frac{25+33}{60}=\frac{29}{30}\).

\(\frac{29}{30}:\frac{2}{15}=\frac{29}{30}\cdot\frac{15}{2}=\frac{29}{4}=7.25\).

Ответ: \(7.25\).