Question

Present age of father is $$42$$ years and that of his son is $$14$$ years
Find the ratio of age of father to the age of son when father was $$30$$ years old.

Answer 1

$$12$$ years ago, the father was $$30$$ years old.
At that time, age of son $$14-12=2$$ years.
Required ratio$$=\dfrac{30}{2}=\dfrac{2\times 15}{2}=\dfrac{15}{1}$$.