Question

If $$\mathrm{P}:\mathrm{Q} = 7 : 4$$ and $$\mathrm{Q}:\mathrm{R} = 5 : 14$$, find $$\mathrm{R}:\mathrm{P}$$.

Answer 1

$$\frac{\mathrm{P}}{\mathrm{R}} = \frac{\mathrm{P}}{\mathrm{Q}} \times \frac{\mathrm{Q}}{\mathrm{R}} = \frac{7}{4} \times \frac{5}{14} = \frac{5}{8}$$.

Thus, $$\frac{\mathrm{R}}{\mathrm{P}} = \frac{8}{5}$$.

Therefore, $$\mathrm{R} : \mathrm{P} = 8 : 5$$.