[計量] 請教排列組合問題

看板GRE (GRE入學考試)作者時間17年前 (2008/08/06 15:51), 編輯推噓2(203)
留言5則, 4人參與, 最新討論串1/1
麻煩各位教我怎麼解.....@@ 我排列組合真的都忘光了...QQ Two different integers are to be selected from a set of 10 different integers in which half of the integers are even and half are odd. How many of the 45 possible selections consist of one even and one odd integer? ANS: 25 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.166.64.14

08/06 16:18, , 1F
C(5,1) x C(5,1) =25
08/06 16:18, 1F

08/06 16:23, , 2F
感謝!! 我知道我的問題在哪了...XD(呆)
08/06 16:23, 2F

08/06 16:59, , 3F
或是 (全部 - 2 odds - 2 evens)
08/06 16:59, 3F

08/06 16:59, , 4F
45 - C(5,2) - C(5,2) = 25
08/06 16:59, 4F

08/06 19:31, , 5F
0有算是integer嗎???
08/06 19:31, 5F
文章代碼(AID): #18cLWVbg (GRE)
文章代碼(AID): #18cLWVbg (GRE)