1."So that was your dad." said Susan. "How old is he?" Roy grinned. "Work it out yourself," he replied. "You're a third as old as he'll be when you're half as old as he is now, and in ten years he'll be twice as old as you'll be." How old?

Roy's father, 40 years (Susan 15)

Roy's father, 46 years (Susan 9)

Roy's father, 42 years (Susan 14)