数学真题一道

efficiency

Factor Percent of Respondents User-friendly 56% Fast response time 48% Bargain prices 42% The table gives three factors to be considered when choosing an Internet service provider and the percent of the 1,200 respondents to a survey who cited that factor as important. If 30 percent of the respondents cited both “user-friendly” and “fast response time,” what is 8 the maximum possible number of respondents who cited “bargain prices,” but neither “user-friendly” nor “fast response time?” A. 312 B. 336 C. 360 D. 384 E. 420 Answer？

HOW DO IT？

快乐公主

B。

56％＋48％－30％＝74％（“user-friendly” and “fast response time,” ）

要想“bargain prices,” but neither“user-friendly” nor “fast response time?”最大

那么“bargain prices,”＋（“user-friendly” and “fast response time,” ＝100％

所以74％＋42％－100％＝16％（交集）

所以“bargain prices,” but neither“user-friendly” nor “fast response time?”＝42％－16％＝28％

28％×1200＝336

elites

42%-16%=26%, 0.26*1200=312, so answer is A