Atotal of 9 women and 12 men reside in the 21 departments that are in a certain apartment building, one person to each apartment. If a poll taker is to select one of the apartments at random, what is the probability that the resident if the apartment selected will be a woman who is a student?
(1)Of the women, 4 are students
(2)Of the women, 5 are not students
抱歉
這題我主要不是不會
想請教一種概括式的概念
因為這題我多想了
覺得(2)不可以
因為不是學生就代表一定是學生嗎
可是他答案就給你出現如此的結局
像之前一題醋與水的混合也是
我想兩者混合後整體容量會改變
所以也給他錯掉
因此我在想是不是在Data Suffience中
只要是非數字方面的題目
偏概念式的題目
一些簡單的假設都應自己考慮進去
而數字方面的題目
就應該特別小心是否等於0之細節
有人可以分享一下嗎
感謝
