Father A is twice the age of the difference in years of the ages of
Father B and Son A, who is one and a half times older than Son B.
Father B is currently twice the age of Son A is going to be when Son B will be double the age he is now.
All of the ages are multiples of five.
How old is Father A?
father a = 70
father b = 50
son a = 15
son b = 10...
there are many more though... such as:
father a = 140
father b = 100
son a = 30
son b = 20...
and so on progressing with son b's age by 10s... these answers, though, don't make much sense in today's world