You can put this solution on YOUR website! Let
Present age of Father = f
Present age of Son = s
Father is now three times as old as his son
f=3s..............(1)
12 years ago means we have to subtract 12 from their present ages
f-12=s-12
then, he was six (times?) as old as his son
f-12=6(s-12)
f-12=6s-72
f=6s-72+12
f=6s-60................(2)
Put the value of f from (1) to (2)
3s=6s-60
3s-6s=-60
-3s=-60
Divide by -3 both sides of the equation
-3s/-3=-60/-3
s=20
Put the value of s in (1)
f=3s
f=3*20
f=60
Present age of Father = f = 60 years old
Present age of Son = s = 20 years old