标题: PREP 数学－52 [打印本页] 作者: allen0018 时间: 2006-9-15 22:06 标题: PREP 数学－52 52. If 500 is the multiple of 100 that is closest to X and 400 is the multiple of 100 that is closest to Y , which multiple of 100 is closest to X +Y
(1) X 小于500
(2) Y 小于 400
这题什么意思阿?
谢谢大家
作者: super_pig 时间: 2006-9-15 22:42
If 500 is the multiple of 100 that is closest to X and 400 is the multiple of 100 that is closest to Y 从这句话，我们知道 550<x<450 , 450<y<350， 1000<x+y<800 单独(1) X 小于500 550<x<500 1000<x+y<850 无法判断which multiple of 100 is closest to X +Y 同理，单独(2)也不行