设随机事件A、B、C两两互斥,且P(A)=0.2,P(B)=0.3,P(C)=0.4,则P(A∪(B-C))=?
解: C' 表示"非C".
P(A∪(B-C)) = P(A∪(BC')) = P(A)+P(BC') = P(A)+P(B)-P(BC) = P(A)+P(B) = 0.5
设随机事件A、B、C两两互斥,且P(A)=0.2,P(B)=0.3,P(C)=0.4,则P(A∪(B-C))=?
解: C' 表示"非C".
P(A∪(B-C)) = P(A∪(BC')) = P(A)+P(BC') = P(A)+P(B)-P(BC) = P(A)+P(B) = 0.5