2.Bag A contains 1 white straw,1 red straw and 2 green straws.Bag B contains 2 white straw,2 red straws and 1 green straw.One straw is drawn at random from each bag.By using a tree diagram,find the probability that
(a)2 straws drawn are of the same colour
(b)1 straw is red and the other one is green
Probability Question
2007-12-20 5:21 am
回答 (1)
2007-12-20 6:52 pm
✔ 最佳答案
Please refer to the page diagram on the following link:http://ustalan.googlepages.com/tree.JPG
(a)2 straws drawn are of the same colour
P(same colour) = P(WW) + P(RR) + P(GG)
= (1/4)*(2/5) + (1/4)*(2/5) + (2/4)*(1/5)
= 6/20 = 3/10
(b)1 straw is red and the other one is green
P(one red + one green) = P(RG) + P(GR)
= (1/4)*(1/5) + (2/4)*(2/5)
= 5/20 = 1/4
希望幫到你
參考: 自己既計算
收錄日期: 2021-05-01 15:40:16
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071219000051KK03566