1)A bag contains two white balls and two black balls. If two balls are drawn randomly from the bag at the same time , the probaility that the white balls are drawn?
2) Three coins are tossed. The probaility that more tails showed than heads is ?
3) If a die is thrown twice , what is the probaility that at least one six appears ?
要式牙唔該!!
probability唔識!!
2008-01-07 2:43 am
回答 (2)
2008-01-07 2:52 am
✔ 最佳答案
1. 係1個white 定2個都white??P(1 white ball) = 2/4 * 1/3 + 2/4 * 1/3 = 1/3
P(both white) = 2/4 * 1/3 = 1/6
2. P( tails more than heads) = 4/8 = 1/2
[no. of choices of 3 coins = 8 (HHH,HHT,HTH,THH,TTH,THT,HTT,TTT)]
3. P(at least 1 '6') = 11/36
參考: myself(:
2008-01-07 2:54 am
1)P(the white balls are drawn)=2/12=1/6
2)P(more tails showed than heads)=4/8=1/2
3)P(at least one six appears)=11/36
2)P(more tails showed than heads)=4/8=1/2
3)P(at least one six appears)=11/36
收錄日期: 2021-04-13 14:53:22
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https://hk.answers.yahoo.com/question/index?qid=20080106000051KK03486