新GRE数学复习要点:Conditional

　　新gre数学的难度相当于高中数学水平，只要大家认真复习，在新gre数学考试中拿高分甚至拿满分都是很有可能的。不过大家也不能忽略新gre数学中可能会出现的考点难点。下面，为大家整理新GRE数学复习要点:Conditional，希望对大家有所帮助。

　　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

　　应对gre数学考试的时候，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。