Question

If A : B = 7 : 5 and B : C = 9 : 14, find A : C.

Answer 1

$\frac{A}{B}=\frac{7}{5}\mathrm{and}\frac{B}{C}=\frac{9}{14}$

Therefore, we have:

$$\begin{gathered} \frac{A}{B}\times \frac{B}{C}=\frac{7}{5}\times \frac{9}{14} \\ \frac{A}{C}=\frac{9}{10} \end{gathered}$$

∴ A : C = 9 : 10