Question

Present age of father is $42\mathrm{years}$ and that of his son is $14\mathrm{years}$. Find the ratio of age of father to the age of son, when son was $12\mathrm{years}$ old.

Answer 1

We have,

Age of father when son was $14\mathrm{years}$ old$=42\mathrm{years}$

Age of father when son was $13\mathrm{years}$ old$=41\mathrm{years}$

Age of father when son was $12\mathrm{years}$ old$=40\mathrm{years}$

$\begin{array}{rcl}\therefore \mathrm{Ratio}\mathrm{of}\mathrm{age}\mathrm{of}\mathrm{father}\mathrm{to}\mathrm{the}\mathrm{age}\mathrm{of}\mathrm{son}& =& \frac{\mathrm{Age}\mathrm{of}\mathrm{father}}{\mathrm{Age}\mathrm{of}\mathrm{son}}\\ & =& \frac{40}{12}\\ & =& \frac{40÷4}{12÷4}\\ & =& \frac{10}{3}\\ & =& 10:3\end{array}$

Hence, required ratio is $10:3$