9.3后数学基金一道题。。。。。。。。。。。。。。。。。

3.There are 1,200 respondents in a survey. And they are divided into three groups, such as A, B and C with percentage of 54%, 36% and 42%(数字抄的梦飞翔的，感觉好像有点出入) respectively (numbers may not be accurate). The percentage of A and B is 30%, what is the maximum number of C that is neither in A nor B. 我选的312，比较确定，算了两遍。

怎么算出312的阿

user-friendly  :1200*56%=672

fast response time : 1200*48%=576

bargain prices : 1200*  1200*42% =504

both ¨user-friendly” and ¨fast response time” : 1200*30% =360

672 + 572  -360 =888

1200-888 = 312

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谢谢Ls

原来是题目中%数字不对哦~~~~~~~~~~