一道典型的交集问题，每次遇到此类都头疼，那位给个思路
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 the maximum possible number of respondents who cited “bargain prices,” but neither “user-friendly” nor “fast response time?” |
|
