00:01
Okay, so for this problem, we're bounded in a world where there are five hats, and two of these hats are red, and three of these hats are blue.
00:14
And then we have three variables, r1, r2, r3, and r1 is alice's hat is red.
00:31
So i'm just going to remind myself that a value of true means red, and a value of false means blue, because that's the value.
00:41
The only other color.
00:42
Our two similarly is b's hat red and r3 is c's hat is red.
00:53
So these people are put in a line so that the back person can see both hats in front, the middle person can see just one hat in front and then the person who's speaking or writing the problem can't see anything in front of her.
01:07
So the first question asks what does it mean to have at most two red hats? so at most two red hats means they can't all be red.
01:19
So that means they can't all be read.
01:25
So r1 and r2 and r3.
01:33
I'm writing this out in sort of regular notation because different classes might write it differently.
01:39
One way you might see this is not r1 and r2 and r3.
01:45
But i want people who don't know those symbols to understand as well.
01:52
So that's having it most two red hats...