20.\frac{5}{3}\cdot2\frac{1}{8}+\frac{5}{8}\cdot1,2.

20. $$\frac{5}{3} \cdot 2 \frac{1}{8} + \frac{5}{8} \cdot 1,2 = \frac{5}{3} \cdot \frac{17}{8} + \frac{5}{8} \cdot \frac{12}{10} = \frac{85}{24} + \frac{60}{80} = \frac{85}{24} + \frac{3}{4} = \frac{85}{24} + \frac{3 \cdot 6}{4 \cdot 6} = \frac{85}{24} + \frac{18}{24} = \frac{103}{24} = 4 \frac{7}{24}$$

Ответ: $$4 \frac{7}{24}$$