Ответ:

  1. \(\frac{2}{3}\cdot\frac{4}{5}=\frac{8}{15}\).
  2. \(\frac{3}{7}\cdot\frac{2}{9}=\frac{6}{63}=\frac{2}{21}\).
  3. \(\frac{5}{6}\cdot\frac{3}{10}=\frac{15}{60}=\frac{1}{4}\).
  4. \(\frac{4}{9}\cdot\frac{3}{8}=\frac{12}{72}=\frac{1}{6}\).
  5. \(\frac{7}{12}\cdot\frac{2}{5}=\frac{14}{60}=\frac{7}{30}\).
  6. \(\frac{1}{4}\cdot\frac{8}{15}=\frac{8}{60}=\frac{2}{15}\).