Ответ:

а) \(0,48+3\frac{1}{6}\cdot2,4=\frac{12}{25}+\frac{19}{6}\cdot\frac{12}{5}=\frac{12}{25}+\frac{38}{5}=\frac{202}{25}=8,08\).

б) \(\left(2,75+0,3\cdot\frac{5}{6}\right)\cdot\frac{2}{3}=\left(\frac{11}{4}+\frac{3}{10}\cdot\frac{5}{6}\right)\cdot\frac{2}{3}=\left(\frac{11}{4}+\frac{1}{4}\right)\cdot\frac{2}{3}=3\cdot\frac{2}{3}=2\).

Ответ: а) \(8,08\); б) \(2\).