[理工]徵求高手解古典機率問題

看板Grad-ProbAsk作者 (小丑程)時間13年前 (2012/10/11 14:21), 編輯推噓1(1推 0噓 8→)
留言9則, 2人參與, 最新討論串1/1
A box contains n identical balls numbered 1 through n. Suppose k balls are drawn in succession. (a.)What is the probability that m is the largest number drawn? (b.)What is the probability that the largest number drawn is less than or equal to m? 我想破頭不知道該如何下手!! 有高手可以教我嗎?!! Help me. please. -- -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 220.130.185.226
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10/11 15:20, , 1F
答案是這樣嗎? 1.(m-1)C(k-1)/nCk 2.(n-m)C(k-1)/nCk
10/11 15:20, 1F
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10/12 09:22, , 2F
可以請問是M-1?
10/12 09:22, 2F
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10/12 10:59, , 3F
你是問m-1怎來的嗎? 那答案是這樣嗎QQ
10/12 10:59, 3F
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10/12 11:17, , 4F
是的!但是我不知道m-1是哪裡來的?
10/12 11:17, 4F
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10/12 11:19, , 5F
m-1是假設第一次拿到的球號碼就比m球號碼大嗎?
10/12 11:19, 5F
推
10/12 13:01, , 6F
你假設有10顆球 每次取五顆球 這樣值域是{6~10}
10/12 13:01, 6F
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10/12 13:02, , 7F
假設m=5 那麼你能取只剩4顆球 m-1 就這樣得到了~
10/12 13:02, 7F
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10/12 13:03, , 8F
更正值域是{5~10}
10/12 13:03, 8F
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10/12 13:04, , 9F
如果是第二題 值域就變成{1~6} m=6可以取的就是10-6(n-m)
10/12 13:04, 9F
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