Question

Find the number which bear the same ratio to $\frac{7}{3}$ that $\frac{8}{21}$ does to $\frac{4}{9}$.

Answer 1

Let the number be $x$. Then,

$x:\frac{7}{3}::\frac{8}{21}:\frac{4}{9}$

$\Rightarrow \frac{x}{\frac{7}{3}}=\frac{\frac{8}{21}}{\frac{4}{9}}$

$\Rightarrow \frac{3x}{7}=\frac{8\times 9}{4\times 21}$

$\Rightarrow x=\frac{8\times 9\times 7}{4\times 21\times 3}$

$\therefore x=2$