数列和概率都是高中数学的重要内容,在近几年的高考试题中,出现了数列与概率的交汇题,这些题目从表面看是以概率题的形式呈现出来的,但需要综合使用数列与概率的主干知识,先探索概率Pn与它的前几项的递推关系,再由求数列的通项公式的方法和手段求解.本文就建立在概率模型中的递 The numbers and probabilities are all important contents of high school mathematics. In the entrance exam questions of recent years, there appear the confluence of numbers and probabilities. These questions are superficially presented in the form of probability questions. However, Probability of the main knowledge, first explore the probability of Pn and its recursion of the first few items, and then by the general method of solving columns and means of solving the problem.This paper is based on the probability model of the delivery