Помогите пожалуйста. Номер 1, 2.

Решите задачу:

$a) \frac{3}{4} \times \frac{1}{5} = \frac{3}{20}$
$b) \frac{7}{20} \times 1 \frac{1}{3} = \frac{7}{20} \times \frac{4}{3} = \frac{28}{60} = \frac{14}{30} = \frac{7}{15}$
$8 \times \frac{5}{6} = \frac{40}{6} = \frac{20}{3} = 6 \frac{2}{3}$
$2. \: a) \frac{2}{3} \div \frac{4}{5} = \frac{2}{3} \times \frac{5}{4} = \frac{5}{6}$
$b) \frac{3}{8} \div 9 = \frac{3}{8} \times \frac{1}{9} = \frac{3}{72} = \frac{1}{24}$
$3. \: { \frac{10}{3} }^{3 } = \frac{10}{3} \times \frac{10}{3} \times \frac{10}{3} = \frac{1000}{27} = 37 \frac{1}{27}$