Logic Riddles

Question: There is a kingdom and in the kingdom when you drink a poison the only way to cure yourself is to drink a stronger poison to neutralize it. The King wants to make the strongest poison possible in order to make sure he can neutralize any other poison he may be given. To do this he enlists the two best chemists of the land: Tom and Bob.

The king is going to have them both create a poison as strong as they can then have them drink the other person's poison then their own. Whoever dies created the weaker poison. Tom knows that Bob is much better at making poisons and he is sure to make a stronger poison. Knowing this, Tom makes a plan that ensures he lives and Bob dies.

The day of the contest arrives and Bob realizes that Tom must have known he had no chance against his prowess as a poison maker. So Bob thinks quickly and creates a new plan that ensures that once again he will live and Tom will die.

In the end Bob lives, Tom dies, and the King doesn't get what he wants.

What happened?

Question: In a marble hall as white as milk, Lined with skin as soft as silk, Within a fountain crystal clear, A golden orb does appear, There are no doors to this stronghold, Yet thieves break in and steal the gold. What am I?

Question: You create your own Where's Waldo game on a piece of paper. You want your friend to find Waldo but they think you might be pulling a prank on them by not putting Waldo on the paper at all.

How can you prove to your friend that Waldo is on the paper without ruining it for them?

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: There are 6 sisters. Each sister has 1 brother. How many brothers are in the sisters' family?