14. \(\left(\frac{3}{20}+\frac{7}{30}\right)\cdot15\)

\(\left(\frac{3}{20}+\frac{7}{30}\right)\cdot15=\left(\frac{9}{60}+\frac{14}{60}\right)\cdot15=\frac{23}{60}\cdot15=\frac{23}{4}=5\frac{3}{4}\).

Ответ: \(5\frac{3}{4}\).