99,回复:Quant面试题:喝醉了(2.5星)

来源: 2009-11-14 10:37:20 [旧帖] [给我悄悄话] 本文已被阅读:

First, the probability of entering the left door is almost one as n goes large.(by an induction formula).
Then it can be derived
E(n+1)=E(n)+1.
Since E(1)=0.
Then E(100)=99.