概率论提高随机事件与概率解答题查看解析已掌握收入错题本题讨论不看本题#10862对任意的事件 A,B,CA,B,CA,B,C,证明:(1) P(AB)+P(AC)+P(BC)≤P(A)+P(B)+P(C)P\left({AB}\right) + P\left({AC}\right) + P\left({BC}\right) \leq P\left(A\right) + P\left(B\right) + P\left(C\right)P(AB)+P(AC)+P(BC)≤P(A)+P(B)+P(C);(2) 当 P(ABC)=12P\left({ABC}\right) = \frac{1}{2}P(ABC)=21 时, P(AB)+P(AC)+P(BC)≥P(A)+P(B)+P(C)−12P\left({AB}\right) + P\left({AC}\right) + P\left({BC}\right) \geq P\left(A\right) + P\left(B\right) + P\left(C\right) - \frac{1}{2}P(AB)+P(AC)+P(BC)≥P(A)+P(B)+P(C)−21.