可以把上面“Open B”改成“Not Car@B”，条件概率定义计算更简单

来源: 于 2024-02-22 22:33:15 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

P(Car@A | Not Car@B)

= P(Car@A & Not Car@B) / P(Not Car@B)

= P(Car@A) / P(Not Car@B) = (1/3) / (2/3) = 1/2

similarly

P(Car@C | Not Car@B)

= P(Car@C & Not Car@B) / P(Not Car@B)

= P(Car@C) / P(Not Car@B) = (1/3) / (2/3) = 1/2

当然了，

P(Car@A | Car@B) = P(Car@C | Car@B) = 0