Logic Riddles

Question: A prison has 23 prisoners in 23 different cells. The prisoners have no way to communicate with each other in any way from their cells. There is another room, the rec room, that has two switches on the wall (A and B). The switches have on and off positions but they start in an unknown position.

Prisoners are randomly taken to and from the rec room one at a time. They must change the position of only one of the two switches each time they go to the room. At any point a prisoner can yell out, "Every prisoner has been here!" If the prisoner is correct that all of the prisoners have visited the rec room, then they all go free. If they aren't correct then they are all executed.

Before they start they are given one planning session during which they can discuss a method to win the game. What method can they use to ensure they all go free?

Question: You walk down a path through the woods everyday. You always walk by one particular large rotting log which weighs over a ton. The next day you notice that there is another large log underneath the familiar one that you've never seen before. How did it get there?

Question: A man looks out to a boat full of people But there's not a single person on board. How is this possible?

Question: If you randomly choose one of the following answers to this question, what is your chance of getting it right?

A) 50%
B) 25%
C) 0%
D) 25%

Question: What am I ?