maths
2008-01-01 2:14 am
In a class of 40 students, there are 24 girls and one quarter of them wear glasses. If a student is chosen at random, what is the chance that who is a girl and does not wear glass
回答 (2)
2008-01-01 2:40 am
✔ 最佳答案
When a student is chosen at randomprobability that the student is a girl
= 24/40
= 3/5
probability that the student does not wear glasses
= 1 -1/4
= 3/4
Therefore, the probability that the student is a girl and at the same time wears glasses is
3/5 x 3/4
=9/20
2008-01-01 2:24 am
24girls,one quarter of them wear glasses.
that means 18 girls do not wear glasses.
there are 40 students in the class,
so the chance is 18/40 = 9/20.
that means 18 girls do not wear glasses.
there are 40 students in the class,
so the chance is 18/40 = 9/20.
參考: me
收錄日期: 2021-04-13 15:31:27
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071231000051KK03219