Heard this one this morning, close to one already posted here though:

Two blondes are walking down the street with duffel bags. Blonde #1 asks blonde #2 what she has in her bag. #2 answers "chickens." #1 says, "If I guess correctly how many chickens you have, can I have one?" #2 answers, "If you guess correctly, you can have them both!" #1 says, "Three."