排列组合问题是中学数学的重要内容之一,不论思考方法还是解题方法都有特殊性:概念性强、灵活性强、思维方法新颖,解题过程易犯“重复”或“遗漏”的错误,并且结果数目较大,无法一一检验,因此给学习带来一定困难.简单的排列组合问题常用捆绑法、插空法、特殊优先法等方法解决, Arranging combinatorial problems is one of the most important parts of high school mathematics. Both the thinking method and the problem solving method have particularity: strong concept, strong flexibility, novel way of thinking, easy to make mistakes of “repeat” or “omission” , And a large number of results, can not be tested one by one, so to bring some difficulties in learning.Such simple permutation and combination problems are often used bundling method, plug-in method, special priority method to solve,