新gre数学重要考点：Conditional

　　2014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。

　　Conditional

　　Probability of event A conditioned on the fact that event B has happened is called the conditional probability and written as P.

　　P=Probability Both A and B happens/ Probability B happens.

　　Example:

　　A six-sided die with faces from 1 to 6 is rolled twice. What is the probability that the face 5 turned up on first try given that the sum of the two faces is 9?

　　P=4/36=1/9.

　　P==1/36.

　　P==1/4.

　　Remember:

　　If P=P,then two events A and B are independent, that is occurrence of one does not influence the other

　　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gre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。