Can anyone give me some information about nHr?
i need detail info.
nHr, nCr,nPr
2007-09-10 5:10 am
回答 (1)
2007-09-10 2:22 pm
✔ 最佳答案
nHr定義nHr = (n+r-1)C(n-1) 或 (n+r-1)Cr (for all whole numbers n,r)
注：這裡的n可以小於r，如2H3 = 4C1 = 4
如在a, b, c中抽出4個字母，字母可重覆出現時，有多少組合方式？(e.g. aabc, bbca...)可以用3H4 = 6C2 or 6C4 = 15
收錄日期: 2021-04-12 01:40:23
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070909000051KK04916