00:01
Here we're asked the probability of having two girls and two boys.
00:02
Let's think about all the outcomes that will give us this.
00:05
We can have two girls and then two boys.
00:08
We can have a girl, boy, girl, boy.
00:13
We can have a girl, boy, boy, girl, boy.
00:19
And we can have a boy, girl, girl, girl, girl.
00:23
We can have a boy, girl, boy, boy, girl.
00:30
We're going to have boy, girl, girl are these let's think about if these are all the combinations here.
00:40
I think it should be an easier way to check this is just to make a treat right.
00:43
We know we're having four children so we're going to have one two, two, three, and finally four.
01:09
And let's say all the left nodes represent girls and all the right nodes represent boys well i could go tight down here so that i don't have to label so everything on this left node is going to give you boy boy boy boy so this is going to be crossed off this is going to be crossed off boy boy girl boy is going to be crossed off so we're going to have one node here then we got boy girl boy girl two nodes here boy girl girl boy boy, three nodes here, boy, girl, sorry, girl, boy, boy, girl...