更新1:
why
maths probability
2008-11-20 2:12 am
a square is divided into 4 regions as shown. There are 5 different colour pens in a box. One is chosen with replacement and is used to paint a region. Find the probability that the colours of the four regions are all different
回答 (2)
2008-11-20 2:38 am
✔ 最佳答案
total no. of choices=5^4=625 (5隻色油4個格)available no. of choices=5x4x3x2=120 (第一格油咩色都得，所以係5，
第二格唔可以同第一格撞色，所以係4，如此類推)
so the probability required=120/625=24/125
參考: i calculated it myself
2008-11-20 2:20 am
應該係甘掛
4 3 2
--- x --- x ---
5 5 5
24
=-----
125
4 3 2
--- x --- x ---
5 5 5
24
=-----
125
收錄日期: 2021-04-24 09:34:13
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20081119000051KK01082