Three men share a room at a hotel.
The manager charged them $30.
So each man payed $10.
The manager realized he charged them too much.
The three rooms totaled only cost $25.
He gave $5 to the porter to return to the men.
The porter didn’t know how to split $5 evenly so he gave each man $1 and kept $2 for himself.
Each man payed $9 (received $1 back).
So the three men payed $27 in total.
The porter had $2.
That comes to $29.
Where is the last dollar?