Question

If the compound ratio of $5:8$ and $3:7$ is $45:x$. Find the value of $x$.

Answer 1

The compound ratio of the given fractions:

$\frac{5}{8}\times \frac{3}{7}=\frac{15}{56}$

$\therefore \frac{15}{56}=\frac{45}{x}$

$\Rightarrow x=45\times \frac{56}{15}=3\times 56=168$

Thus the value of $x=168$