This was a riddle my dad liked to share. I first heard it in the fifties, which explains the dollar amounts.
Three traveling salesmen went to a hotel to get a room. The desk clerk only has one room left, but it was large enough to accommodate all of them. It would be $30.00. The men agreed that this was okay, and pay ten dollars each.
After the men go to their room, the desk clerk realizes he overcharged them—the room should have been $25.00. He gave the bellboy five dollars to return to the men.
The bell boy didn’t just fall off the turnip truck—he knew there was no way to split up the five dollars evenly among the three men. He pockets two dollars and returns three dollars to the men. They could easily share that refund. The men were happy to have saved a dollar each and the bell boy is two dollars richer.
To review: the men originally paid $30.00, or ten dollars each. Then, they each received a one-dollar refund. Simple math therefore confirms they paid $27.00 (10 – 1 = 9; 9 x 3 = 27). The bell boy kept two dollars for himself. $27 (the amount they collectively paid) plus the $2 the bellboy kept for himself equal $29.00. Any nine-year-old can confirm that.
Where is the other dollar?