What will come in place of the question mark (?) in the following questions?
$$\frac{21}{25} \times \frac{75}{56} \times \frac{32}{33} = ?$$
$$\frac{5}{7} + \frac{2}{3} - \frac{2}{7} = ? $$
$$42 \%$$ of $$12\%$$ of $$\frac{1}{4}$$ of $$15000 = ?$$