a) $$3 \frac{1}{11} + 2 \frac{3}{22} = 3 \frac{2}{22} + 2 \frac{3}{22} = 5 \frac{5}{22}$$
б) $$3 \frac{1}{3} - 1 \frac{1}{5} = 3 \frac{5}{15} - 1 \frac{3}{15} = 2 \frac{2}{15}$$
в) $$4 - 2 \frac{4}{7} = 3 \frac{7}{7} - 2 \frac{4}{7} = 1 \frac{3}{7}$$
Ответ: а) $$5 \frac{5}{22}$$; б) $$2 \frac{2}{15}$$; в) $$1 \frac{3}{7}$$