新东方小编在此与大家分享新GRE数学备考的相关内容，希望各位在2015年能够搞定GRE数学真题。

　　本文为大家准备了GRE数学考试重要考点知识，便于考生GRE考试备考。

　　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.

　　A set can not have repeating member:{1,3,1,2}is not a set.

　　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.

　　更多关于GRE考试2014年终盘点及2015备考规划的内容，请关注新东方网GRE频道，也可通过下方二维码关注我们的微信平台(微信号：GRE-XDF)。

　　备战2015年GRE考试，新东方最新GRE热课必将成就你的理想。

微信号：GRE-XDF

(实习编辑：刘伯罡)