作者wassili (咎由自取)
看板Statistics
標題[問題] 問一個期望值的問題
時間Fri Feb 17 21:41:41 2006
One of four different prizes was randomly put into each box of a cereal.
If a family decided to buy this cereal
until it obtained at least one of each of the four different prizes,
what is the expected number of boxes of cereal that must be purchased?
想了很久...試過很多種想法算出來都不對= ="
請教板上的高手了
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1F：推 mangogogo:折價卷問題 這之前就有人問過了 02/17 21:43
2F：→ mangogogo:1699 給你參考 02/17 21:44
3F：推 wassili:感謝.這類題型從正面去思考實在很難了解 02/17 22:34