单选题 There are 35 applicants applying for the position. 20 of them have experience, 13 of them are older than 25 years old, and 5 have no experience and are younger than 25 years old. How many of the applicants have experience and older than 25 years old?
【正确答案】 E
【答案解析】假设集合A为有工作经验的人，那么A=20，假设集合B为大于25岁的人，那么B=13，小于25岁并且没有工作经验的人用集合N=5表示，代入公式得到：35=20+13-O+5，因此O=3，选择E。