00:02
We're looking at a bag, and we know that this bag has three green.
00:04
So i'm going to call them g1, g2, g3, and then it has four blue.
00:10
So i'd call it b1, b2, b3, b4.
00:15
And first of all, we want to find out how many elements are in the sample space.
00:21
And then they want us to list all the possibilities now.
00:23
Now i'm not going to list them all down, but i'll start it out.
00:26
So think of, and there's no replacement.
00:29
So when you pull one out, you don't put it back.
00:31
So the first time when i pull a marble out, there are seven marbles that are available.
00:35
Now i keep the one and hold on to it, and then i'm going to draw another one out.
00:40
And there are six possibilities.
00:41
So there are 42 items in my sample space.
00:45
Now, to list them all out, you can do it in an organized fashion, in a charting form.
00:51
And typically, i do something like this.
00:53
I just start with the first one and say, i could pull out g1 and then i could pull out g2.
00:58
Leave g1 alone.
00:59
I could pull out g1 and g3.
01:02
I could pull out g1 first and then b1.
01:06
I could pull out g1 first and then b2.
01:09
I could pull out g1 first and then b2...