You can put this solution on YOUR website! Not enough information here for a definitive answer.
Let's say the son is 10. Then the mother could be 20 and the father 25.
Or maybe the son is 15. Then the mother could be 30 and the father 35.
Son is 20. Mother is 40 and father is 45.
etc etc
Are you sure there isn't another line to this problem?