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标题: 难题请教，各位给参详一下！ [打印本页]

作者: JohnDong 时间: 2009-11-7 08:23
标题: 难题请教，各位给参详一下！
Town T has 20000 residents , 60 percent of whom are female . What percent of the residents were born in Town T ?

(1) The number of female residents who were born in Town T is twice the number of male residents who were not born in Town T.

(2) The number of female residents who were not born in Town T is twice the number of male residents who were born in Town T .

假设born female占总人数百分比：x ，born male：y ；求x+y？

（1）20000*x=2*(20000*(1-0.6-y)) => x+2y=0.8

(2) 20000*(0.6-x)=2*20000*y => x+2y=0.6

本体应该无解吧，答案却是有解，是我理解题目有问题吗？

作者: zhaoke27 时间: 2009-11-7 08:54
我跟你的思路一样哦，怎么回事？

作者: verylotus 时间: 2009-11-7 10:07
同问

作者: loveyj613 时间: 2009-11-7 11:32
我也觉得是啊。。。
请nn解答下~~谢谢！

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