3 一個包含正反面的公正的銅板投擲 3 次,現定義 A = {出現正面奇數次},..-阿摩線上測驗
1F Bruce 大二下 (2016/07/05)
投擲公正銅板3次 S:{(HHH),(HHT),(HTH),(HTT),(TTH),(THT),(THH),(TTT)} 樣本S個數=2^3=8 定義 事件A = {出現正面奇數次} = {(HHH),(HTT),(TTH),(THT)} 則P(A) = 4/8 = 1/2 事件B = {至少出現正面 1 次} = {(HHH),(HHT),(HTH),(HTT),(TTH),(THT),(THH)} 則P(B) = 7/8 P(A∩B) = {既出現正面奇數次,也至少出現正面1次} = {(HHH),(HTT),(TTH),(THT)} = 4/8 = 1/2 P (A∪B) = P(A) + P(B) - P(A∩B) = 1/2 + 7/8 - 1/2 = 7/8 = 0.875 |
2F
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