$$1 - \frac{38}{55} = \frac{55}{55} - \frac{38}{55} = \frac{55 - 38}{55} = \frac{17}{55}$$
$$\frac{33}{34} \cdot \frac{17}{55} = \frac{33 \cdot 17}{34 \cdot 55} = \frac{3 \cdot 1}{2 \cdot 5} = \frac{3}{10}$$
$$\frac{13}{20} : \frac{13}{25} = \frac{13}{20} \cdot \frac{25}{13} = \frac{13 \cdot 25}{20 \cdot 13} = \frac{1 \cdot 5}{4 \cdot 1} = \frac{5}{4}$$
$$\frac{5}{4} = 1 \frac{1}{4} = 1,25$$
$$\frac{3}{10} + \frac{5}{4} = 0,3 + 1,25 = 1,55$$
Ответ: 1,55