题目

英语翻译
In the UEFA Euro 2004 playoffs draw 10 national football teams were matched in
pairs.A lot of people complained that “the draw was not fair,” because each strong
team had been matched with a weak team (this is commercially the most interesting).
It was claimed that such a matching is extremely unlikely.We will compute the
probability of this “dream draw” in this exercise.In the spirit of the three-envelope
example of Section 2.1 we put the names of the 5 strong teams in envelopes labeled
1,2,3,4,and 5 and of the 5 weak teams in envelopes labeled 6,7,8,9,and 10.
.We shuffle the 10 envelopes and then match the envelope on top with the next envelope,
the third envelope with the fourth envelope,and so on.One particular way a “dream
draw” occurs is when the five envelopes labeled 1,2,3,4,5 are in the odd numbered
positions (in any order!) and the others are in the even numbered positions.

提问时间：2021-03-13

答案

在2004欧锦赛季后赛画10国家足球队是匹配的
对.很多人抱怨说,“画是不公平的,“因为每个强
团队已经与一个弱队(这是商业上最有趣的).
据说,这样的匹配是非常不可能的.我们将计算
概率的这种“梦画”在这个运动.在精神的三个信封
2.1节的例子我们把名字的5强队在信封标签
1、2、3、4、5和5弱队在信封上标记的6、7、8、9和10.