Logic Riddles

Question: Who was buried in Grant's Tomb?

Question: A man was driving a black car. His lights were off. The moon shown no light. A cat was in the middle of the road. How did he know to stop?

Question: Three guests check into a hotel room. The clerk says the bill is $30, so each guest pays $10. Later the clerk realizes the bill should only be $25. To rectify this, he gives the bellhop $5 to return to the guests. On the way to the room, the bellhop realizes that he cannot divide the money equally. As the guests didn't know the total of the revised bill, the bellhop decides to just give each guest $1 and keep $2 for himself. Each guest got $1 back: so now each guest only paid $9; bringing the total paid to $27. The bellhop has $2. And $27 + $2 = $29 so, if the guests originally handed over $30, what happened to the remaining $1?

Question: There are 5 houses painted 5 different colors. In each house lives a person with a different nationality. These 5 people each drink a certain type of beverage, smoke a certain brand of cigar, and keep a certain pet. None of them have the same pet, smoke the same brand of cigar, or drink the same beverage.

The Brit lives in the red house.
The Swede keeps dogs as pets.
The Dane drinks tea.
The green house is on the left of the white house.
The green homeowner drinks coffee.
The person who smokes Pall Mall rears birds.
The owner of the yellow house smokes Dunhill.
The man living in the center house drinks milk.
The Norwegian lives in the first house.
The man who smokes Blend lives next to the one who keeps cats.
The man who keeps the horse lives next to the man who smokes Dunhill.
The owner who smokes Bluemaster drinks beer.
The German smokes prince.
The Norwegian lives next to the blue house.
The man who smokes Blend has a neighbor who drinks water.

Who owns the fish?

Question: 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?