Question: Father is three times as old as his son. If the difference of their ages is 24 years, find their present ages.

Solution:

Let the present age of the father be 'x' years and that of son be 'y' years.

According to the question,

Condition I,
Father is three times as old as his son,
$or, x = 3y$ - (i)

Condition II,
The difference of their ages is 24 years,
$or, x - y = 24$

Put the value of x from equation i in equation ii, we get,

$or, 3y - y = 24$
$or, 2y = 24$
$or, y = \frac{24}{2}$
$\therefore y = 12$

Now,

Put the value of y in equation (i), we get,

$or, x = 3×12$
$\therefore x = 36$

So, (x,y) = (36,12)

Therefore, the present ages of the father and the son are 36 years and 12 years respectively.