Logic Riddles

Question: A man challenges the greatest chess player in the world to two games of chess. He guarantees that he will win or tie at least one of the games for sure. To be even more cocky, the man says he will play both games at the same time.

How does he guarantee he wins or ties at least one game?

Question: What temperature is twice as hot as 0 degrees Celsius?

Question: A man is doing some work on his home and goes to a hardware store. He goes up to the clerk and tells him what he wants. The clerk tells him that each one is $1. He tells the clerk he would like 5000 and he is charged only $4.

What did he buy?

Question: A man murders his wife with a knife in their car. Nobody is around to see this. He throws her out of the car being careful not to leave any fingerprints on her body. Next he throws the knife off of a cliff into a gorge where it will never be found and he goes home. An hour later the police call him and tell him that his wife has been murdered and he needs to come to the scene of the crime immediately. As soon as he arrives, he is arrested.

How did they know he did it?

Question: You have two books. One of them is upside-down and the other is rotated so the top of the book is facing you.

What is the sum of the first page in each book?