Question

若事件A,B独立,且P（A U B）=0.6,P（A）=0.4,则P（B）=?

Answer 1

ecause

P(AUB)=p(A)+P(B)-P(AB)

and because

A、B相互独立

so P(AB)=P(A)*P(B)

so P(AUB)=p(A)+P(B)-P(AB)=P(A)+P(B)*[1-p(A)]

代入可得P(B)=1/3