Age

Sally's age is 12 years plus half her age. How old is she?

Billy is twice as old as Sally was when Billy was as old as Sally is now. And the total of their ages is 28. How old are they?

Suzy is ten years older than Billy, and next year she will be twice as old as Billy. How old are they now?

A man is nine times as old as his son. In nine years, he will be only three times as old as his son. How old are each now?