I am three times as old as my son. Five years later, I shall be two and a half times as old as my son. How old I am and how old is my son?
Let, the age of my son is x years.
Then my age is 3x years.
Five years hence my son's age will be x+5 and that of mine will be 3x+5.
According to the problem,
3x+5=212(x+5)
or, 3x+5=52(x+5)
or, 6x+10=5x+25
or, x=15.
So my son is 15 years old and my age is 45 years.