Question

A father is 30 years older than his son. In 12 years, the man will be three times as old as his son. Find their present ages.

Answer 1

$\begin{array}{l}\text{Let the age of the son and the father be}x\mathrm{yrs}\text{and}(x+30)\mathrm{yrs},\mathrm{respectively}.\\ \mathrm{According}\mathrm{to}\mathrm{the}\mathrm{question},\mathrm{we}\mathrm{have}:\\ \begin{array}{l}\text{3}\times (x+12)=x+30+12\\ \text{⇒3}x+36=x+42\\ \Rightarrow \text{3}x-x=42-36\\ \Rightarrow \text{2}x=6\\ \Rightarrow x=3\\ \therefore \mathrm{Son}\text{'}\mathrm{s}\mathrm{a}\text{ge}=3\text{yrs}\\ \text{Father's age}=(x+30)\mathrm{yrs}=(3+30)\mathrm{yrs}=33\text{yrs}\end{array}\end{array}$