【#GRE# 导语】成功=时间+方法,自制力是这个等式的保障。世上无天才,高手都是来自刻苦的练习。而大家往往只看到“牛人”闪耀的成绩,忽视其成绩背后无比寂寞的勤奋。以下为“GRE数学重要知识点:组合”,欢迎阅读参考!更多相关讯息请关注®文档大全网!
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.