1. When Amy is twice as old as Ruth was when Amy was half Ruth's present age, Ruth will be half again as old as Amy will be when Ruth is half again as old as Amy is now. One of them is in her fifties, and we have taken ages in complete years. You work it out!

Ruth 41 years old, Amy 33

Ruth 54 years old, Amy 44

Ruth 51 years old, Amy 46