00:01
Okay, so for part a, we want to list all of the elements of the sample space.
00:09
And so what we have to do is consider all the different boards here, and we can consider all the combinations of two boards per ordered pair.
00:20
So we have 1 .2, 1 .3, 1 .4, because the boards are all 1, 2, 3, 4, 2 comma 4 and 2 .5, 2 .5.
00:42
And then we have 3 .4, 3 .5, and 4.
00:47
So this gives us our sample space.
00:54
Now for part b, we have that x can only take on the values 0, 1, or 2, as in 0 defective boards, 1 defective board, 2 or 2 defective boards.
01:09
So the probability of 0 is equal to probability of x, equals 0, which means we're not including boards 1 or 2, since they're the only defective ones.
01:20
So we have probability of the set of elements 3 .4, 3 .5, and 4.
01:32
Which means since the sample space has 10 elements, we have a probability here of 3 over 10, because each element of the sample space is equally likely since we're choosing at random.
01:52
So this is 0 .3...