Three men stop at a motel for the night.  The rate for a room is $30,
so each man throws in $10.

After they've gone to the room, the desk clerk realizes he's actually
overcharged them (there's a special for 3 in a room) and the rate is only $25.
The desk clerk gives the bellhop $5 change to take to the three men.

On the way to the room, the bellhop thinks, "There are 3 of them;
$5 doesn't evenly divide by 3 and they'll never know..." so he pockets $2
and gives the men the remaining $3.

Problem - Each of the men has now paid $9 ($10 - $1 back) and the bell hop
has $2 in his pocket.  Thats $29 ((3x9)+2).
But the men originally paid $30.

What happened to the other dollar?