00:03
We're going to have three children, and we want to draw a tree diagram of all possible combinations of genders.
00:10
And we want to know, then, what is the probability of having at least one of each gender? all right.
00:15
So let's first draw our tree diagram out for this.
00:18
So with our first child, we have either a male or a female.
00:23
All right.
00:24
And if the first one was a male, well, then the second child is either a male or a female.
00:30
But if the first one was a female instead, yeah, it's still either a male.
00:34
Male or a female.
00:36
All right.
00:37
And if i had two males, well then my third child is either a male or a female.
00:42
And we hopefully get the idea here, male, female, from each of these male, female, male, and then female.
00:51
All right.
00:52
So that's what our tree diagram would actually look like.
00:55
I like to actually write out the combinations that these represent.
00:59
Now we assume it's a 50 -50 shot for being a male or a female.
01:02
That's what we have to go on in this.
01:04
I think in real life it's not exact, but it's certainly close enough that we can just use the 50%.
01:10
So this first one here, right? this right down here, means that we had a male, then a male, then a male.
01:16
So we had three boys, basically.
01:18
All right.
01:18
So that's the combination, male, male, male.
01:21
This one is male, male, and then a female.
01:24
So we had two sons first and then a daughter.
01:27
All right...