00:01
For part a, we want to compute the probability that the ball selected from the second earn is white.
00:12
There are two cases.
00:15
That is, the board selected from the first earn is white, and then the board selected from the second earn is white as well.
00:34
Note that this is a conditional probability.
00:40
The second case is that the earn selected from the first one, sorry, the board selected from the first earn is right, but the board selected from the second earn is white.
01:00
For the first case, since there are two white balls and four red balls in the first earn, the probability that the board selected from the first earn is white is 2 over 2 plus 4.
01:19
And now there are two white balls and one right balls in the second earn.
01:27
So the probability that we selected a white ball as 2 over 2 plus 1.
01:36
For the second case, the probability that we selected a right ball is 4 over 2 plus 4...