Counting Rules點計？
請用中文解釋一下...
更新1:
咁我點知個Ｎ係成幾多呢﹑ 咁個Ｐ又係Ｄ咩？
Counting Rules
回答 (1)
2007-12-30 6:37 am
✔ 最佳答案
P 係排列意思囉n 係 total 共幾多數咩
x 係取幾多數咩
! 係階乘
for e.g
n for 6, x for 2
it can be write down as
6P2 = 6! / ( 6 - 2 )! = 6! / 4! = 6 * 5 * 4! / 4! = 6 * 5 = 30
P.S 6! = 6 * 5 * 4 * 3 * 2 * 1
參考: 自己
收錄日期: 2021-04-19 00:05:39
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071219000051KK03137