Question (Probability)
2009-01-14 7:33 am
Bag A contains 4 white balls and 2 black balls. Bag B contains 2 white balls and 3 black balls. A ball is drawn at random from bag A and is put in bag B. Then a ball is drawn at random from bag B. What is the probability that the ball drawn is black?
回答 (1)
2009-01-14 8:06 am
✔ 最佳答案
No. of balls in Bag A
= 4 + 2
= 6
No. of balls in Bag B
= 2 + 3
= 5
P(black drawn at B)
= P(black from A, then black drawn at B) + P(white from A, then black drawn at B)
= (2/6) x (4/6) + (4/6) x (3/6)
= (8/36) + (12/36)
= 20/36
= 5/9
=
收錄日期: 2021-04-29 18:16:33
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090113000051KK02105