A man is thrice as old as his son. Five years ago ago the man was four times as old as his son. Find their present ages.

1 answer

now:
son's age --- x
man's age --- 3x

5 years ago:
son's age = x-5
man's age = 3x-5

3x-5 = 4(x-5)

solve and the mystery will be unravelled.