Logic Riddles

Question: If you have a cake, how many pieces of cake can you form with 3 straight cuts?

Question: Two children are born in the same hospital, on the same year, on the same day, and have the same father and mother. But they are not twins.

How is this possible?

Question: A woman is in the hospital for a routine procedure. The doctor leaves the room locking the door before he goes, the woman is alone. The doctor comes back to find the woman has died and there is another person is in the room. The door was still locked.
How is this possible?

Question: There is a chain nailed to the wall. The chain is 10 feet long and the center of the chain dips down 5 feet from where each side of the chain is nailed to the wall. How far are the 2 ends of chain from each other?

Question: Every time a man lies his nose grows to 150 percent of its size. Every time he tells the truth it shrinks to 50 percent of its size.

What will happen if he alternates between lies and the truth?