排列与组合都是用来计算在特定情况下所有可能情形的方法,他们之间的最主要区别就是在解题时是否需要考虑顺序的问题.在解决组合问题时不需要考虑元素的顺序问题,但是排列问题却需要考虑元素在组合时的顺序问题.显然,排列问题比组合问题更为棘手.只有严格按照排列组合问题的解题原则进行,解题速度才能提高.一、排列组合问题的解题原则(一)审题要仔细 Arrangement and combination are used to calculate all possible situations in a particular case of the method, the most important difference between them is that in the problem-solving need to consider the order of the problem.In the solution to the combination of problems do not need to consider the sequence of elements, However, the arrangement of the problem need to consider the order of elements in the combination of the order.Obviously, the arrangement of problems is more difficult than the combination of problems.Only in strict accordance with the principle of solving the problem of permutation and combination, the speed of problem-solving can be improved. Question principle (a) examines the topic carefully