There are10000 lottery tickets in a box,
each with a unique number from 0000 to 9999 printed on it.
If a ticket is drawn at random,
find the probabilities that the ticket number satisfies the following conditions:
(a) The last digit is divisble by 3.
(b) The last digits are the same.
(c) The last 3 digits are 123, 456 or 789
(a)(b)(c)三題各列式+解說唔該.....
急用.....15分@@!
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There are10000 lottery tickets
2011-12-06 4:51 am
回答 (2)
2011-12-06 6:09 pm
✔ 最佳答案
a) The last digit is divisble by 3that means there only 3 cases for every 10 tickets
= 3/10 = 0.3
b) The last 2 digits are the same
that means there are only 10 cases for every 100 tickets
= 10/100 = 0.1
c) The last 3 digits are 123, 456 or 789
that means there are only 3 cases for every 1000 tickets
and overall probabilities = 3/1000 = 0.003
2011-12-06 5:17 am
a For the last digit is divisible by 3 , the last digit must be 3 or 6 or 9
No. of tickets =3*1000=3000
probabilities=3000/10000=0.3
b) The last two digits are the same, they can be 00,11,22,33,44,55,66,77,88,99
No. of tickets=10*100=1000
probabilities=1000/10000=0.1
c) No. of tickets=3*100=300
probabilities=300/10000=0.03
No. of tickets =3*1000=3000
probabilities=3000/10000=0.3
b) The last two digits are the same, they can be 00,11,22,33,44,55,66,77,88,99
No. of tickets=10*100=1000
probabilities=1000/10000=0.1
c) No. of tickets=3*100=300
probabilities=300/10000=0.03
收錄日期: 2021-04-15 17:00:30
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111205000051KK00795