作者Arfeo (闪)
看板Math
标题[机统] 抽签的期望值?
时间Mon May 2 10:08:20 2011
欸..想问一下机率的问题
下面是我在其他课本中看到的叙述:
... the expected number of draws required to draw one red ball out of a
bin containing n red balls and N-n grenn balls is (N+1)/(n+1)
if the balls are not replaced.
想问一下这是怎麽推出来的QQ
谢谢:)
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 140.115.210.76
1F：→ Arfeo :少打 if the balls are not replaced ..XD 05/02 10:09
2F：推 sa12e3 :按大E修改! 05/02 10:10
※ 编辑: Arfeo 来自: 140.115.210.76 (05/02 11:10)