A man is 28 years older than his son. After 10 years, he will be thrice as old as his son. Find their present ages.

Let the son's present age be x years.

Then, the man's present age = (x + 28) years.

After 10 years:

Son's age = (x + 10) years.

Man's age = (x + 28 + 10) years = (x + 38) years.

According to the question, after 10 years, the man will be thrice as old as his son:

∴ x + 38 = 3(x + 10)

⇒ x + 38 = 3x + 30

⇒ x - 3x = 30 - 38 $\quad$ [Transposing +38 to RHS and +3x to LHS]

⇒ -2x = -8

⇒ x = $\dfrac{-8}{-2}$

⇒ x = 4

Son's present age = x years = 4 years.

Man's present age = (x + 28) years = (4 + 28) years = 32 years.

Hence, the man's present age is 32 years and his son's age is 4 years.