Probability

2009-03-18 1:00 am
Alan goes to school either by minibus or by taxi. The probability of being late for school is 1/10 if he travels by minibus and 1/15 if he travels by taxi.



Qs:
If Alan is equally likely to go to school by minibus or by taxi on one day, find the probability that he will be late on that day.

回答 (3)

2009-03-18 1:32 am
✔ 最佳答案
P(Alan will be late for school)

= P(by minibus) * P(late by minibus) + P(by taxi) * P(late by taxi)

= (1/2) (1/10) + (1/2) (1/15)

= 1/12
2009-03-18 7:09 am
P(Alan will be late for school)

= P(by minibus) .P(late by minibus) + P(by taxi) . P(late by taxi)

= (1/2) (1/10) + (1/2) (1/15)

= 1/12

因為Alan goes to school either by minibus or by taxi,所以P(E)係1件條件概率,所以當佢搭巴士果陣,個條件係巴士,即係同的士E2個選擇中既其中1個,而遲到既機會率就係1/10,,所以在巴士條件下遲到既機率=(1/2) (1/10),,而的士既概率都係一樣既計法,,,因為整件事件中,,佢有機會係因的士遲,,亦都有機會因巴士而遲,,所以P(Alan will be late for school)=(1/2) (1/10) + (1/2) (1/15)= 1/12
2009-03-18 1:07 am
The probability that he will be late on that day

0.5*0.1 + 0.5*0.15

0.125

2009-03-17 17:39:50 補充:
0.0833333333333333333 才對

2009-03-17 17:41:59 補充:
0.5*0.1 + 0.5*0.066666666666666
參考: myself


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