$\frac{7}{20} \times \frac{6}{19} \times \frac{5}{18}$

$\frac{7}{20} \times \frac{7}{20} \times \frac{7}{20}$

$\frac{7}{20} + \frac{6}{19} + \frac{5}{18}$

$\frac{7}{20} \times \frac{6}{20} \times \frac{5}{20}$