00:01
For this problem to begin, we know that we have three red marbles, two blue marbles, and one green marble.
00:14
We're told that we draw two from the bag without replacement.
00:23
Replacement.
00:24
Replacement.
00:29
So we're first asked to create a probability tree for this scenario.
00:33
So we can see that we start out with a total of six marbles.
00:37
Our first branching is, well, going to be corresponding to which color do we get on that first draw.
00:44
We can get red, blue, i hope you can't hear my cat yelling in the background.
00:50
We get red, blue, or green.
00:53
We know that there are three red and six in total, so the probability of red would be three over six, or just one over two.
01:00
We know that there are two blue out of six, so the probability of getting blue would be one over three.
01:06
And there's one green out of six, so the probability of getting green is one over six.
01:11
6.
01:12
Then we branch off again, r, g, or b.
01:21
But now the probabilities have changed.
01:24
If we have drawn a red marble from the set of 6, well, we're sampling without replacement.
01:29
So that means that there are now only 2 red marbles and 5 marbles to choose from...