After you collect 4 different kinds of coupons, you can get a free meal.
On average, how many meals do you expect to buy before you can get a free one?
更新1:
...and there are totally 4 different kinds of coupons.
Probability quest.
2010-05-02 7:58 am
In a restaurant, if you buy a meal you can randomly get a coupon and there are totally 4 coupons.
After you collect 4 different kinds of coupons, you can get a free meal.
On average, how many meals do you expect to buy before you can get a free one?
After you collect 4 different kinds of coupons, you can get a free meal.
On average, how many meals do you expect to buy before you can get a free one?
回答 (2)
2010-05-02 8:41 am
✔ 最佳答案
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2010-05-02 00:41:56 補充：
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2010-05-05 11:41 pm
收錄日期: 2021-04-23 23:21:48
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100501000051KK02001