數學題(Combination)#3 10分
2011-12-12 9:51 pm
圖片參考：http://imgcld.yimg.com/8/n/HA00145646/o/701112120024913873410220.jpg
ans: 21b=120 c=6075
請解釋以上問題,thanks
回答 (1)
2011-12-12 11:52 pm
✔ 最佳答案
(21b)It means all committee member came from either Central Canada or Western Canada
10C7
= 10C3
= 10 * 9 * 8 / (3 * 2 * 1)
= 120
(21c)
all combinations = 15C7
no representation from Eastern Canada : 10C7 = 120
no representation from Central Canada : 10C7 = 120
no representation from Western Canada : 10C7 = 120
At least one representative from each region of Canada :
15C7 - 3 * 120
= 6435 - 360
= 6075
收錄日期: 2021-04-13 18:24:05
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111212000051KK00249