that's easy,Bob is twice as old as jack,so he is now thirty.

that's easy,Bob is twice as old as jack,so he is now thirty. Jack is twice as old as Jill, when david is twice as old as he is now he will four times a when David is twice as old as he is now he will be four time the man is now twice as old as the woman was when he was old Jack is twice as old as Jill ,but in five years time he will 一到英语竞赛智力题,When David is twice as old as he is now he will be 一个英语竞赛智力题When David is twice as old as he is now he will be Jack is twice as oid as bill. 猜猜看（英语）Jack is twice as old as Bill,who is eight years young 英语翻译Jack is twice as old as Bill,who is eight years younger jack is twice as old as Bill,who is 8 years younger lhan Ben