事件的機率
考慮投擲一個公平的骰子所可能的結果, 分別為 1,2,3,4,5,6, 6面出現的可能性都相等,
樣本空間為
,
則各別元素的機率為
, outcome equally likely. 稱為 uniform probability model
假設事件 A 為表示投擲點數大於 4 的事件, 則
,

When the elementary outcomes are modeled as equally likely, we have a uniform
probability model. If there are k elementary outcomes in S, eachis assigned
the probability of 1/k.
An event A consisting of m elementary outcomes is then assigned