Insight · ★★☆☆☆ · ~3 min
The Missing Dollar
$27 + $2 = $29. But they paid $30. A dollar just vanished — or did it?
by MindYourPuzzle
Three guests check into a hotel room and pay $30 — $10 each.
Later, the clerk realizes the room was only $25 and sends the bellboy up with $5. The bellboy, unable to split $5 three ways, quietly pockets $2 and returns $1 to each guest.
Now count it up: each guest has paid $10 − $1 = $9. Three guests × $9 = $27. Add the bellboy's $2 — that's $29.
They started with $30. Where is the missing dollar?
Hints