新gre数学重要考点：set、排列、组合.pdf

智 课 网 G R E 备 考 资 料 新gre数学重要考点 set 排列 组合 2011新gre考试实施以来 不仅对写作部分茫然不知所措 就连我 们所擅长的数学也甚是担忧 相信这其中的原因还是由于考生在新gre 数学复习时没有把基础打牢 如果新版gre数学基本考点都没有复习到 如何能拿到分数呢 所以说 想要新版gre数学考好 复习的时候一定 要把基本概念和重要考点都弄扎实 Set A set is a collection of objects or things Each object in a set a member or element of that set Size of a set is the number of members in the set Example The set of even numbers between 2 and 10 is of size 5 2 4 6 8 10 The set of primes between 2 and 10 is of size 4 2 3 5 7 Remember Each member of set A belongs to A or is in the set A Rearranging the order of the members does not change the set 1 2 3 is same as 3 2 1 Combinations Number of ways we can select n objects from a group of m distinct objects is m n m n Example Number of possible ways to pick 4 oscar nominations from a list of 50 movies is 50 4 50 4 50 4 46 50 49 48 47 24 230300 Remember This does not apply if there are identical objects Permutation of Objects The number of ways n distinct objects can be ordered is n Example Number of ways 6 people can from a queue is 6 Number of ways 5 different cars can be parked in 5 parking spaces is 5 Remember This does not apply if there are identical objects or ordering does not matter 由于美国数学基础教育的难度增加导致数学考试越来越难 但新gr e数学复习考点都是高中时候学到的知识点 考生不要过于紧张 把基 本概念弄明白 再记住一些新版gre数学必备的词汇 那么相信新版gre 数学应该没有问题