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- 精华
- 1
- 积分
- 1975
- 经验
- 1975 点
- 威望
- 182 点
- 金钱
- 657 ￥
- 魅力
- 494
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prep 一道古典概率题
A certain junior class has 1,000 students and a certain senior class has 800 students. Among these students, there are 60 sibling pairs, each consisting of 1 junior and 1 senior. If 1 student is to be selected at random from each class, what is the probability that the 2 students selected will be a sibling pair?
答案没破解。不过希望大家能指导一下方法 |
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