Question

Huilan is 8 years younger than Thomas. The sum of their ages is 76. What is Thomas's age?

Answer 1

Let H denote the age of Hullan.

Let T denote the age of Thomas.

Huilan is 8 years younger than Thomas

Mathematically,

$H=T-8\qquad eq.1$

The sum of their ages is 76.

Mathematically,

$H+T=76\qquad eq.2$

Now let us substitute eq. 1 into eq. 2

$\begin{gathered} H+T=76 \\ (T-8)+T=76 \\ T-8+T=76 \\ 2T-8=76 \\ 2T=76+8 \\ 2T=84 \\ T=\frac{84}{2} \\ T=42 \end{gathered}$

Therefore, the age of Thomas is 42 years.