July 8, 2025 · 6:17 am

Age Question (Year 8 equation solving)

Eight years ago my father was three times as old as I shall be in five years time. When I was born he was 41 years old. How old am I now?

I always find these age questions a bit weird – a bit of a riddle, and contrived (just so we can solve some equations)

Let $x$ be my age now, and $y$ be my fathers age now.

(1) $\begin{equation*}y=x+41\end{equation*}$

Because my father was 41 when I was born.

(2) $\begin{equation*}y-8=3(x+5)\end{equation*}$

$y-8$ for 8 years ago, and $3(x+5)$ for three times my age in 5 years.

Solve the equations simultaneously. Substitute $y=x+41$ into equation $2$

$\begin{equation*}x+41-8=3(x+5)\end{equation}$

$\begin{equation*}x-33=3x+15\end{equation}$

$\begin{equation*}18=2x\end{equation}$

$\begin{equation*}x=9\end{equation}$

Hence my current age is $9$ .

Recent Posts