3 men book into a $30 hotel room.Each man pays $10.
The hotel manager realizes he has made a mistake and the hotel room is only $25.
So he gives the bellboy $ 5 to return to the men .
The bellboy thinks to himself .5 divided by 3 wont go so I will pocket $2 and give them $1 each back.
So the 3 men have now effectively paid $9 each.
3 by 9 equals $27. $2 in the bellboys pocket = $29 .
WHERE HAS THE OTHER $1 gone.

Cheers.
darky