- UID
- 923920
- 在线时间
- 小时
- 注册时间
- 2013-8-15
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
A certain manufacturer of cake, muffin, and bread mixes has 100 buyers, of whom 50 purchase cake mix, 40 purchase muffin mix, and 20 purchase both cake mix and muffin mix. If a buyer is to be selected at random from the 100 buyers, what is the probability that the buyer selected will be one who purchases neither cake mix nor muffin mix?
(A) 1/10
(B) 3/10
(C) 1/2
(D) 7/10
(E) 9/10
答案是B ， 求解释， 非常感谢！ |
|
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2014-1-5 22:07:46
收藏
收藏
