Question

Số?

Answer 1

$\frac{1}{2} \times \frac{1}{2} = \frac{1}{4}$    ;       $\frac{2}{3} \times \frac{4}{5} = \frac{8}{{15}}$     ;     $\frac{3}{4} \times \frac{3}{4} = \frac{9}{{16}}$