00:01
All right.
00:01
So in this question, we are taking an item from box a and an item from box b.
00:06
And the first part is, what is the probability that one is defective and one is not? there's two ways of doing that.
00:18
We could get a defective item from a, non -defective from b, defective from b, non -defective from a.
00:24
So we have to do each of those probabilities.
00:26
So the probability of a being defective is three out of eight.
00:30
The probability of b being not defective is three out of five.
00:35
And then we have the probability of a being not defective and b being defective.
00:42
So two out of five.
00:43
That gives us nine out of 40 plus 10 out of 40, which is 19 out of 40 .475.
00:53
So then b, we know that that is occurring.
00:56
So we're only interested in this 47 and a half percent of the time...