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标题: 一道折磨我的题,求救!谢谢!! [打印本页]

作者: pychina 时间: 2007-12-11 23:12
标题: 一道折磨我的题,求救!谢谢!!

For a recent play performance, the ticket prices were $25 per adult and $15 per child. A total of 500 tickets were sold for the performance. How many of the tickets sold were for adults?
(1) Revenue from ticket sales for this performance totaled $10,500.
(2) The average (arithmetic mean) price per ticket sold was $21.
我选的是E,而答案是D,请问是不是答案错了?

作者: 东岸老男人 时间: 2007-12-11 23:23

同学，这是个2元一次方程啊，假设成人一共卖a张，小孩卖了c张

从第一个条件可以知道

25a+15c=10500

a+c=500

这个方程你会解吧？

从第二个条件可知道：

a+c=500

（25a+15c)=21X500

这个方程你会解吧？

所以是都单独可以。

你一定是看漏了条件。：）

作者: pychina 时间: 2007-12-11 23:26

晕,老大,神人啊,我确实漏看了!结果选的是C~非常感谢

作者: pychina 时间: 2007-12-11 23:26

晕,老大,神人啊,我确实漏看了!结果选的是C~非常感谢

作者: sunnyblue13s 时间: 2007-12-11 23:30

答案應該是D吧~~

X+Y=500

1.)25X+15Y=10500

2.)21*500=10500

只要補足其中一項皆可~~ 答案應該是D囉~~

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