a man is twice as old as his son.twenty years ago,the father was four times as old as the son.find the age of each now.

The man is twice as old as his son:

s = 2m

20 years ago, the man was 4x as old as the son:

(m-20)*4 = (s-20)

4m-80=2m-20

2m=60

m=60

The man is now 60, the son is now 30