this was probably posted here before but reading a book and read it
Three travelers came to a motel and decided to share one room. The clerk registered them for $30. Each of the travelers pitched in $10. After a bit, the clerk realized that the special rate for that day was $25, so he gave the bellhop $5 and told him to take it to the travelers. On his way to the room, the bellhop reasoned that he couldn't split $5 three ways, so he'd just return $3 to the travelers and keep the other $2.
Therefore, each of the travelers wound up paying $9 for his room. Since 9 X 3 is 27, and the bellhop kept $2, what happened to the other dollar (27 + 2 = 29)?