請麻煩解答 以下幾條問題
1(a) How many distinct word can be made from the letters "a", "b", "c", "i", "s"??
(b) How many distinct word can be made from the letters "c", "i", "b", "i", "c"??
(c)In how many ways can a team of 4 boys and 3 girls be formed from 8 boys and 6 girls?
2. A die is weighted( i.e. its NOT a fail die). When it is tossed the probability of a number showing up is proportional to the number. Find the probability of getting an even number.
3. In a class, 35% of the students failed English, 20%of the students failed Mathematics, and 10% of the students fail both English and Mathematics. A student is randomly selected.
(a) Find the probability that he fail Mathematics given that he failed English.
(a) Find the probability that he fail English given that he failed Mathematics.
(a) Find the probability that he fail Mathematics or English.
4. In a school, 4% of the boys and 3% of the girls are taller then 1.8m. It is known that 40% of the students are girls. If a student randomly selected is taller than 1.8m, what is the probability that the student is a girl?
幫忙 解答..謝謝各位,我的STAT PROB 方面真係好差
數學 概率PROB問題
2013-04-15 6:39 am
回答 (1)
2013-04-17 12:42 am
✔ 最佳答案
1. (a) 5! = 120(b) (5P3) /2 = 30
(c) 8C4 * 6C3 = 1400
2. 錯別字：fail ---> fair
2/(1+2+3+4+5+6) + 4/21 + 6/21 = 12/21
3. (a) 0.1/0.35 = 2/7
(b) 0.1/0.2 = 1/2
(c) 0.35 + 0.2 - 0.1 = 0.45
4. Let girls be G, taller than 1.8m be T, boys be B
P(G) = 0.4
P(T ︳G) = 0.03
P(T&G) = 0.03 * 0.4 = 0.012
P(B) = 1 - 0.4 = 0.6
P(B&T) = 0.6 * 0.04 = 0.024
P(T) = 0.012 + 0.024 = 0.036
P(G ︳T) = 0.012/0.036 = 1/3
坦白講，其實我1(a) 同1(b) 都唔太肯定，如果有錯我會盡力改回
參考: 自己
收錄日期: 2021-04-13 19:25:05
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130414000051KK00344