Math
5K: WS
everyone else: none

Riddles
A criminal is brought into a prison for major crimes. The warden informs him that he will be shot in the middle of the prison by 20 of his men. The prisoner is fine with that but he asks for some conditions "All of your men must stand 20 feet away from me and I must be able to select where each of them stands. If I survive, I get to leave."

The warden thinks about it and knows that all of his men will still have an open shot at the criminal, so he agrees.

The next day immediately after the firing squad is positioned the criminal walks out untouched. How did he do it?: 10 tiger paws
There is a prison with 100 prisoners, each in separate cells with no form of contact. There is an area in the prison with a single light bulb in it. Each day, the warden picks one of the prisoners at random, even if they have been picked before, and takes them out to the lobby. The prisoner will have the choice to flip the switch if they want. The light bulb starts off.

When a prisoner is taken into the area with the light bulb, he can also say "Every prisoner has been brought to the light bulb." If this is true all prisoners will go free. However, if a prisoner chooses to say this and it's wrong, all the prisoners will be executed. So a prisoner should only say this if he knows it is true for sure.

Before the first day of this process begins, all the prisoners are allowed to get together to discuss a strategy to eventually save themselves.

What strategy could they use to ensure they will go free?: 10