计算机问题求解一论题2-7，离散概率基础2018年04月18日
计算机问题求解 – 论题2-7 - 离散概率基础 2018年04月18日
问题1：你能否给我们讲讲书上那个关于邮购商店的“故事”，那里什么地方体现了“碰运气”？
If we havea tablewith 100buckets and 50keys to put in those buckets.it is possible that all 50 of thosekeys could be assigned (hashed)to thesame bucket in the table.However,someone who is experienced with usinghash functions will tell you that you'd never see this in a million years.But that same person might also tell you that neither would you ever seein a million years, all the keys hash into differentlocations, In fact, it is farless likelythat all 50keys would hash into one place than that all 50keyswould hash into different places, but both events are quite unlikely.Beingable to understand just how likely or unlikely such events are is a majorreason for taking up the study of probability.间题2：这里的youdnever..和neitherwouldyouever...有什么意义?
离散概率模型问题3：你能否以下面的过程为例解释离散概率模型中的主要概念？OutcomeSample spaceEventprobabilityAprocess：掷两个色子两次
离散概率模型 A process: 掷两个色子 Outcome Sample space Event probability 两次
Axioms for a probability space满足下列性质的P称为一个probabilitydistribution或者一个probabilitymeasure。1.P(A)≥OforanyACS2.P(S)=13.P(AUB)=P(A)+P(B)foranytwodisjointeventsAandB记住：P是一个函数。问题4：为什么任何事件的概率值不会大于1？如果A和B相交，P（AUB）是什么？
Axioms for a probability space 满足下列性质的P称为一个probability distribution 或者一个 probability measure。 记住：P 是一个函数