$A=\underset{20\text{razy}}{\underbrace{\frac{7}{35}+\frac{7}{35}+\dots +\frac{7}{35}+\frac{7}{35}}}={\sout{20}}^4\cdot \frac{7}{{\sout{35}}^7}=4\cdot \frac{7}{7}=4\cdot 1=4$   

$B=\underset{35\text{razy}}{\underbrace{\frac{4}{36}+\frac{4}{36}+\dots +\frac{4}{36}+\frac{4}{36}}}=35\cdot \frac{{\sout{4}}^1}{{\sout{36}}^9}=\frac{35}{9}=3\frac{8}{9}$    

 

$4>3\frac{8}{9}\text{stąd}A>B$