请教一个概率题目 - 未名空间MITBBS历史存档

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请教一个概率题目

请教一个概率题目# JobHunting - 待字闺中

s*r2010-01-19 08:01

1 楼

let's say A keep tossing a fair coin, until he get 2 consecutive heads,
define X to be the number of tosses for this process; B keep tossing another fair coin, until he get 3 consecutive heads, define Y to be the number of the tosses for this process.
Calculate P{X>Y}
看到了这个题目, 我只会算出现HH和HHH的需要仍的期望值, 这个就不知道怎么算了

s*s2010-01-19 08:01

2 楼

You can still use Markov chain to calculate this, set the state to be 2
variable truple (X,Y)

another fair coin, until he get 3 consecutive heads, define Y to be the
number of the tosses for this process.

【在 s*****r 的大作中提到】

: let's say A keep tossing a fair coin, until he get 2 consecutive heads,
: define X to be the number of tosses for this process; B keep tossing another fair coin, until he get 3 consecutive heads, define Y to be the number of the tosses for this process.
: Calculate P{X>Y}
: 看到了这个题目, 我只会算出现HH和HHH的需要仍的期望值, 这个就不知道怎么算了