来自师建国的问题
【设P(A)=0.4,P(B)=0.3,P(A∪B)=0.4,则P(A.B)=______.】
设P(A)=0.4,P(B)=0.3,P(A∪B)=0.4,则P(A.
B)=______.
1回答
2020-05-19 01:37
【设P(A)=0.4,P(B)=0.3,P(A∪B)=0.4,则P(A.B)=______.】
设P(A)=0.4,P(B)=0.3,P(A∪B)=0.4,则P(A.
B)=______.
由和事件的基本性质可得:
P(A∪B)=P(A)+P(B)-P(AB)
故:
P(AB)=P(A)+P(B)-P(A∪B)=0.4+0.3-0.4=0.3
P(A.
B