概率作为考查学生应用能力的载体,在近年高考中出现频频,条件概率引入以后,多数学生由于对概率知识理解不透,加上问题中往往融入复杂的计数问题,使得学生时常出错.下面结合实际和易出现的问题,对条件概率的概念进行解读,与同学们交流.定义设A,B为两个事件,且P(A)>0,称P(B |A)=P(AB)/P(A)为在事件A发生的条件下,事件B发生的条件概率. Probability as a test of student ability to use the carrier, appeared in college entrance examination frequently in recent years, the introduction of conditional probability, the majority of students because of the understanding of the probability of knowledge, coupled with the problem often incorporates complex counting problems, making students often go wrong. (A) = P (AB) / P (A)> 0, and P (A)> 0, P (B | A) = P P (A) is the conditional probability that event B occurs under the condition that event A occurs.