设A,B为随机事件,且P(A)=0.4,P(B)=0.3,P(A+B)=0.6,则P(A否B)等于多少?
问题描述:
设A,B为随机事件,且P(A)=0.4,P(B)=0.3,P(A+B)=0.6,则P(A否B)等于多少?
答
P(A)=0.4,P(B)=0.3,P(A or B)=0.6
P(A and B) = P(A)+P(b) -P(A or B)
=0.4+0.3-0.6=0.1