The boy’s sign reads “1 cup for 25¢, 3 cups for $1
A construction worker stops by and asks to buy one cup of lemonade. “25 cents”, says the kid.
The construction worker then buys another one, and another one, paying 25 cents each.
As the construction worker walks away, he turns around with a smile, and says: “Hey kid, you realize I just bought three cups for 75¢… Maybe lemonade stands aren’t your thing.”
“I guess you’re right” says the kid good-naturedly as he sets up the next 3 cups.