$$a) \frac{9}{52} \cdot 4 \frac{1}{3} \cdot \frac{1}{3} + (3 \frac{2}{3} + 2 \frac{4}{5}) \cdot \frac{60}{97} + \frac{5}{36} \cdot 1 \frac{4}{5} = \frac{9}{52} \cdot \frac{13}{3} \cdot \frac{1}{3} + (\frac{11}{3} + \frac{14}{5}) \cdot \frac{60}{97} + \frac{5}{36} \cdot \frac{9}{5} =$$ $$\frac{9 \cdot 13 \cdot 1}{52 \cdot 3 \cdot 3} + (\frac{55}{15} + \frac{42}{15}) \cdot \frac{60}{97} + \frac{5 \cdot 9}{36 \cdot 5} = \frac{1 \cdot 1 \cdot 1}{4 \cdot 1 \cdot 1} + \frac{97}{15} \cdot \frac{60}{97} + \frac{1 \cdot 1}{4 \cdot 1} = $$ $$\frac{1}{4} + \frac{1}{1} \cdot \frac{4}{1} + \frac{1}{4} = \frac{1}{4} + 4 + \frac{1}{4} = 4 + \frac{2}{4} = 4 \frac{1}{2} = 4,5$$
Ответ: 4,5