Good Riddles

Question: A thief enters a shop and threatens the clerk, forcing him to open the safe. The clerk says, "The code for the safe is different every day, and if you hurt me you'll never get the code". But the thief manages to guess the code on his own.

How did he do it?

Question: A hobo picks up cigarette butts from the ground and can make a cigarette with 4 butts. If he finds 16 cigarette butts, how many cigarettes can he make?

Question: There are three jars full of equal amounts quarters, dimes, and penny's. Which one has the highest value?

Question: I make up all literature, but I'm often sealed.

What am I?

Question: I go into the water red and come out black.

What am I?