Ответ:

  1. Сократим множители крест-накрест: \(\frac{6}{25}\cdot\frac{5}{12}=\frac{1}{5}\cdot\frac{1}{2}=\frac{1}{10}\).
  2. \(\frac{15}{22}\cdot\frac{11}{20}=\frac{3}{4}\cdot\frac{1}{2}=\frac{3}{8}\).
  3. \(\frac{7}{4}\cdot\frac{12}{35}=\frac{1}{1}\cdot\frac{3}{5}=\frac{3}{5}\).
  4. \(\frac{18}{5}\cdot\frac{40}{9}=2\cdot8=16\).
  5. \(\frac{2}{15}\cdot\frac{3}{8}=\frac{1}{5}\cdot\frac{1}{4}=\frac{1}{20}\).
  6. \(\frac{6}{11}\cdot\frac{15}{8}\cdot\frac{22}{5}=\frac{3}{1}\cdot\frac{3}{4}\cdot\frac{2}{1}=\frac{18}{4}=\frac{9}{2}\).
  7. \(\frac{3}{10}\cdot\frac{35}{36}\cdot\frac{24}{7}=\frac{1}{1}\cdot\frac{5}{3}\cdot\frac{2}{1}=\frac{10}{3}\).
  8. \(\frac{20}{3}\cdot\frac{9}{28}\cdot\frac{14}{75}=\frac{4}{1}\cdot\frac{3}{1}\cdot\frac{1}{15}=\frac{12}{15}=\frac{4}{5}\).
  9. \(\frac{30}{19}\cdot\frac{13}{100}\cdot\frac{20}{39}=\frac{3}{19}\cdot\frac{13}{10}\cdot\frac{1}{39}=\frac{39}{7410}=\frac{1}{190}\).
  10. \(\frac{16}{5}\cdot\frac{15}{14}\cdot\frac{63}{24}=\frac{2}{1}\cdot\frac{3}{7}\cdot\frac{9}{2}=\frac{27}{7}\).