Question 464507
A father is thrice as old as his son . Five years Ago , he was four times as old. How old is the father?

Let x = age of the son
   3x = age of the father

3x-5 = 4(x-5)
3x-5 = 4x -20
20-5 = 4x -3x
x = 15
3x = 3(15) = 45

The father is 45 years old.