Maths Probability
2007-10-22 3:58 am
1.Calvin takes the MTR or a bus to school every day, and the probability that he takes the MTR is 3/5. If he takes the MTR to school, the probability of him being late is 1/4; if he takes a bus to school, the probability of him being late is 2/5. Find the probability that he is late on a certain day.
回答 (3)
2007-10-22 4:07 am
✔ 最佳答案
The required probability= (3/5)(1/4) + [1-(3/5)](2/5)
= 3/20 + (2/5)(2/5)
= 3/20 + 4/25
= 15/100 + 16/100
= 31/100
Explanation:
(3/5) = P(by MTR)
(1/4) = P(late|by MTR)
[1-(3/5)] = P(by bus)
(2/5) = P(late|by bus)
If there is a mistake, please inform me.
參考: My Maths knowledge
2007-10-22 9:42 am
(3/5 x 1/4) + (2/5 x 2/5)
= 3/20 + 4/25
= 31/100 or 31%
= 3/20 + 4/25
= 31/100 or 31%
2007-10-22 4:05 am
應該係咁
3/5 x 1/4 + 2/5 x 2/5
= 3/20 + 4/25
= 31/100
唔知o岩唔o岩
3/5 x 1/4 + 2/5 x 2/5
= 3/20 + 4/25
= 31/100
唔知o岩唔o岩
收錄日期: 2021-04-13 14:04:33
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071021000051KK04641