There was a business man driving down this country road when he spotted a little boy that had a lemonade stand.  It being hot and him being thirsty, he decided to stop.

Once he got up to the little boy's stand, he noticed a sign that said "All you can drink 10 cent," and a single, very small glass. 

Well, he thought that it was an awful small glass, but since it was only 10 cents for all you can drink, he decided to get some anyway.

He gave the boy a dime, and shot down the whole glass in one swig.  He slapped the glass back onto the table and said, "fill 'er up."

The kid replieds, "Sure thing, that'll be 10 cents."

To this the business man said, "But your sign says all you can drink for a dime."

"It is," the little boy replies, "that's all you can drink for a dime."