Question

设A,B为两个随机事件,0一楼，我还是看不明白你写的，P(AB逆)/P(B逆) =P(A)-P(AB)/1-P(B)是说

Answer 1

P(A/B逆）=P(AB逆)/P(B逆) =P(A)-P(AB)/1-P(B)

P(A/B) =P(AB)/P(B)

因为P(A/B逆）=P(A/B)

所以P(A)-P(AB)/1-P(B)=P(AB)/P(B)

所以P(A)+P(B)=1

所以A与B相互独立