Three people check into a room. The bill is $30. They split it 3 ways. Later on the hotel realizes they should have charged $25 so they send a bellhop to return $5. The bellhop realizes he can't split $5 3 ways to he gives each person $1 and keeps $2.
They have now paid $9 each for the room, the bellhop has $2.
$27 + $2 = $29
What happened to the last $1 considering $30 was originally paid.
The bellhop has $2. This $2 is covered by the $27 paid by the guests. Don't add it to the $27.
The guests have had $3 in total returned to them.
$30 - $3 = $27 (of which $2 is the bellhops).
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