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标题: 数学题求解答 [打印本页]

作者: Aimee_728 时间: 2015-11-28 22:55
标题: 数学题求解答
[attach]172183[/attach]

请问e self-employed butnot married的人数如何确定？在延伸一下，married but not selt－employed的人数呢？

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作者: Aimee_728 时间: 2015-11-29 07:47

求会的大神指教～

作者: liangchao819 时间: 2015-11-29 13:31
是A吗？？？？

作者: DANIELLLLLL 时间: 2015-11-29 17:36
25% of those who are married are self- employed，156*25%=39，39个人结婚且self- employed，那self- employed的70个人里，有70-39=31个人没结婚，然后用31/248=1/8，选A。

作者: DANIELLLLLL 时间: 2015-11-29 17:39
use matrix if you like, it will be more clear.
               self-employed Not self-employed
Married          39                                        156
Not-married    31
                  70                                        248

作者: Aimee_728 时间: 2015-11-29 22:56

liangchao819 发表于 2015-11-29 13:31
是A吗？？？？

是滴，选a

作者: Aimee_728 时间: 2015-11-29 22:58

DANIELLLLLL 发表于 2015-11-29 17:36
25% of those who are married are self- employed，156*25%=39，39个人结婚且self- employed，那self- emp ...

好的，懂了，谢谢～

作者: Aimee_728 时间: 2015-11-29 23:06

DANIELLLLLL 发表于 2015-11-29 17:39
use matrix if you like, it will be more clear.
self-employed Not self-employed
M ...

            self－employed Not self－employed
Married       39                            117                   156
Not-married 31                            61                   92
                  70                         178                   248

我这样理解对吗？谢谢回复哟～

作者: liangchao819 时间: 2015-11-30 09:49

Aimee_728 发表于 2015-11-29 22:56
是滴，选a

酱紫，首先他说了156 married，然后25％是self-employed,然后156*0.25＝39，70人又知道是总共的self-employed，然后70－39＝31 最后31除总数248就知道是1／8啦

作者: Aimee_728 时间: 2015-12-1 18:12

liangchao819 发表于 2015-11-30 09:49
酱紫，首先他说了156 married，然后25％是self-employed,然后156*0.25＝39，70人又知道是总共的self-empl ...

好滴，懂啦，谢谢～

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