[機統] 一題機率的問題

看板Math作者 (freejustice)時間14年前 (2011/11/19 16:50), 編輯推噓1(101)
留言2則, 1人參與, 最新討論串1/3 (看更多)
完整題目是 Electric current is transmitted from point A to point B provided at least one of the circuits #1 through #n below is closed. If the circuits closed independently of each other and with respective probabilities p_i, i=1,...,n, determinethe probability that: i) Exactly one circuit is closed; ii) At least one circuit is closed; iii) Exactly m circuits are closed for 0 <= m <= n; iv) At least m circuits are closed with m as in part (iii); v) What do parts (i)-(v) become for p_1=p_2=‧‧‧=p_n=p, say? 大概的意思是一個電流從A到B至少要有一條電路是通路(closed) 現在有n條電路 各自closed的機率是p_1到p_n 上面的意思應該對吧 我不知道有沒有誤解題目的意思 i)的答案我算是 n Σ p_i(1-p_1)...(1-p_i-1)(1-p_i+1)...(1-p_n) i=1 不知道對不對 ii)應該是1-(1-p_1)(1-p_2)...(1-p_n) iii) (iv) 就不太會了 可以教我嗎? 謝謝 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 112.104.160.70

11/19 18:50, , 1F
第三個是剛好m條(所以就C(n,m)然後類似)
11/19 18:50, 1F

11/19 18:50, , 2F
第四個是至少m條(看你要用扣的還是加的)
11/19 18:50, 2F
文章代碼(AID): #1EnstDJF (Math)
文章代碼(AID): #1EnstDJF (Math)