a) $$\frac{4}{11} < \frac{6}{11}$$, т.к. 4 < 6
b) $$\frac{7}{19} < \frac{7}{11}$$, т.к. 19 > 11
в) $$\frac{7}{27} > \frac{5}{27}$$, т.к. 7 > 5
г) $$\frac{6}{13} < \frac{13}{4}$$, т.к. $$\frac{6}{13} < 1$$, а $$\frac{13}{4} > 1$$
д) $$\frac{3}{7} < \frac{9}{7}$$, т.к. 3 < 9
e) $$\frac{9}{16} > \frac{7}{16}$$, т.к. 9 > 7
ж) $$\frac{11}{31} < \frac{11}{21}$$, т.к. 31 > 21
з) $$\frac{8}{23} > \frac{5}{23}$$, т.к. 8 > 5