Question

Express the situation algebraically. "I am three times as old as my son. Five years later, I shall be two and a half times as old as my son" .

Answer 1

Let my age be x & son's age be y.

$x=3y$

$(x+5)=2.5(y+5)$

$\Rightarrow (3y+5)=\frac{25}{10}(y+5)$

$\Rightarrow 3y+5=\frac{5}{2}(y+5)$

$\Rightarrow 3y+5=\frac{5}{2}(y+5)$

$\Rightarrow 6y+10=5y+25$

$\Rightarrow y=15$

$\Rightarrow x=3y=45$.