少妇AV一区二区三区无|久久AV电影一区三|日本一级片黄色毛片|亚洲久久成人av在线久操|黄色视频在线免费看呀一区二区|综合精品视频精品久久久浪朝|亚洲午夜成人资源|欧美黄色一级片黑寡妇|内射无毛少妇特写|无码农村夜晚偷拍啪啪

GRE數(shù)學(xué)重要知識(shí)點(diǎn):組合

時(shí)間:2019-12-02 09:47:00   來(lái)源:新東方在線     [字體: ]

【#GRE留學(xué)外語(yǔ)考試# #GRE數(shù)學(xué)重要知識(shí)點(diǎn):組合#】成功=時(shí)間+方法,自制力是這個(gè)等式的保障。世上無(wú)天才,高手都是來(lái)自刻苦的練習(xí)。而大家往往只看到“牛人”閃耀的成績(jī),忽視其成績(jī)背后無(wú)比寂寞的勤奮。以下為“GRE數(shù)學(xué)重要知識(shí)點(diǎn):組合”,歡迎閱讀參考!更多相關(guān)訊息請(qǐng)關(guān)注©無(wú)憂考網(wǎng)!





  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.