一道数学真题

xiongxiong88

today rose is twice as old as sam and sam is 3 years younger than tina. if rose, sam,and tina are all alive 4 years from today, which of the following must be true on that day?

I. rose is twice as old as sam
II. sam is 3 years younger than tina
III. rose is older than tina

A) I only
B) II only
C) III only
D) I and II
E) II and III

请问，大家是怎么判断出III不是正确答案呢？正确答案是B。谢谢大家，能给个具体的推导过程吗？谢谢大家帮助笨笨的自由。