高中数学新教材第二册中增加了概率的内容.本文试 图就同学们解概率题时易犯的错误类型作些总结,供同学 们参考. 类型一:“非等可能”与“等可能”混同 例1 掷两枚骰子,求事件A为出现的点数之和等于3 的概率. 错解 掷两枚骰子出现的点数之和的可能数值为 {2,3,4,…,12},有利于事件A的结果只有3,故P(A)=1/11. 分析 公式P(A)=有利于事件A的基本事件数/基本事件的总数 仅当所 The contents of Probability are added to Book 2 of the New High School Mathematics Textbook. This paper attempts to summarize some of the types of errors the classmates tend to make when solving probabilistic questions, for reference by classmates. Type One: “Non-Equal Possible” and “ Such as possible ”mix the same example 1 throw two dices, ask the event A is the probability of the sum of the number of points appear equal to 3. The number of possible miscalculation of the sum of the number of points to throw two dice is {2,3,4,..., 12}, the result of favoring event A is only 3, so P(A) = 1/11. The analysis formula P(A) = the number of basic events that favor event A / the total number of basic events only when