哪位做了输血jj329的帮头脑混乱的我解答下 已解决

yuantengxuanwu

329.【foxlzl】有X、Y两个数，问X的40%是否大于Y的35%?
条件1：X是Y的90%
条件2: 0.5<X<1.5, ??<y<?? (就x和y的范围，具体数字不记得了，反正不充分)选A
参考答案：
条件一：充分 x=0.9y→0.36y大于0.35y


问下大家这个条件一
如果就是只知道整数，当xy同为正，可以得出大于关系，当同为负得到小于关系。这种讨论的两种关系，叫做推出来了吗？是不是就不是充分了啊 。
记得是有两个结果出来就不算做充分了，对吧，现在比较混乱了，麻烦大家！

wayne5198

Exactly, what if the number will be negative, the condition 1 should not be the correct answer. Unless the article did mention that x and y are positive.
For instance: x= 9 , y=10  40%x=3.6 > 3.5=35%y
                   x=-9, y=-10  40%x=-3.6 < -3.5=35%y
Therefore, the given answer should not be correct. In my opinion

yuantengxuanwu

Exactly, what if the number will be negative, the condition 1 should not be the correct answer. Unless the article did mention that x and y are positive.
For instance: x= 9 , y=10  40%x=3.6 > 3.5=35%y
                   x=-9, y=-10  40%x=-3.6 < -3.5=35%y
Therefore, the given answer should not be correct. In my opinion

-- by 会员 wayne5198 (2011/11/22 14:31:52)

谢ls童鞋帮忙解答确认啊