例 1.3.4easy一级题目发布者: ai-batch题干例 1.3.4 已知事件 AAA，BBB，A∪BA\cup BA∪B 的概率分别为 0.4,0.3,0.60.4,0.3,0.60.4,0.3,0.6。求 P(ABˉ)P(A\bar{B})P(ABˉ)。答案点击展开后可查看解析解析由加法公式 P(A∪B)=P(A)+P(B)−P(AB)P(A\cup B)=P(A)+P(B)-P(AB)P(A∪B)=P(A)+P(B)−P(AB) 及题设条件知 0.6=0.4+0.3−P(AB),0.6=0.4+0.3-P(AB),0.6=0.4+0.3−P(AB), 由此解得 P(AB)=0.1,P(AB)=0.1,P(AB)=0.1, 所以再由（1.3.4）式得 P(ABˉ)=P(A−B)=P(A)−P(AB)=0.4−0.1=0.3.P(A\bar{B})=P(A-B)=P(A)-P(AB)=0.4-0.1=0.3.P(ABˉ)=P(A−B)=P(A)−P(AB)=0.4−0.1=0.3.