Off-topic
Spoiler:
Three men: $30
Bellboy: $0
Hotel: $0
Pay:
Three men: $0
Bellboy: $0
Hotel: $30
Return $5 through Bellboy:
Three men: $0
Bellboy: $5 (in bills of $1)
Hotel: $25
Return $3 to men:
Three men: $3
Bellboy: $2
Hotel: $25
So everything adds up.
The men pay $27 for the room, of which $25 ends up in the hotel's account, and $2 stays in the bellboy's pocket. You are missing that one dollar because the men got returned one dollar more than the bellboy stole.
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On a similar note, do you know this joke on the circle of debts?
A customer walks into a hotel and wants to rent a room for $50. He says: "I'll put $50 on the counter, and I'll take a look upstairs, OK? If I like the room, I'll rent it." "OK," says the hotel owner. As soon as the customer is upstairs, the hotel owner grabs the $50, and runs over to the baker, to pay an $50 debt he has with him. The baker, in turn runs to the hairdresser to pay a $50 bill. The hairdresser runs to... and so on. 15 minutes after the hotel owner first ran out with this $50, a prostitute walks into the hotel, and says: "Here's the $50 I still owe you for that room I rented last week."
The hotel owner puts the $50 back on the counter. At that point, the customer comes down the stairs, and says: "Sorry, but I don't like your rooms," picks up the $50, and leaves the hotel.
Thus, all debts in the entire village were resolved.