题目内容：

一个GRE数学题
Of the 700 members of a certain organization,120 are lawyers.Two members of the organization will be selected at random.Which of the following is closet to the probability that neither of the members selected will be a lawyer?
0.5 0.6 0.7 0.8 0.9

优质解答

题目意思明白吧?数学问题就是700选2,这2个不在120中,即剩下的580选2占700选2的概率：