概率问题是高中数学新增的重要问题 ,具有实践性和操作性强的特点 ,它融许多分支于一体 ,形成了一个新的“交汇点” .下面列举概率计算中的两类数列递推关系的几个例子 .1　一阶递推型例 1　已知正四面体A -BCD ,有一只小虫自顶点A沿每一条棱以等可能的概率爬到另外三个顶点B , Probability problem is an important new problem in high school mathematics. It has the characteristics of practicality and operability. It integrates many branches into one and forms a new “convergence point.” The following lists the recursive relations between two types of sequences in probability calculations. A few examples.1 First-order recursive type 1 Known regular tetrahedron A-BCD, a small bug crawls to the other three vertices B from vertex A along each edge with equal probability,