It's Black and White!
There are four boys who agree to a challenge. There are two wearing black hats and two wearing white hats and none of the the boys know who is wearing which hat color. They are challenged to be the first to say, with certainty, which color their own hat is.
The following is all true:
Three of the boys (Danny, Ryan, and Christof) are all on one side of a solid wall, all facing the wall and in the order listed, such that Danny is closest to the wall. Danny can only see the wall, Ryan can see Danny's hat, and Christof can see both Danny's and Ryan's hats.
The other boy, Tim, is on the other side of the solid wall and can't see any of the other boys.
- Christof is wearing a WHITE hat.
- Ryan is wearing a BLACK hat.
- Danny is wearing a WHITE hat.
- Tim is wearing a BLACK hat.
Which boy is the only one who can know, for certain, what color their hat is and says it first?