Three girls share a hotel room. They each give $100 for the $300 room. Later, the clerk discovers it should be $250. She gives $50 to the attendant to take too the girls. Unable to divide the money 3 ways, he gives each girl $10 and pockets $20. Now each girl has paid $90 each, making a total of $270 for the room, the attendant has $20. Where is the other $10

There is $250 with the clerk, $20 with the attendant and $30 with the girls.

The $270 is fictitious, and should be regarded as $250 with the clerk and $20 with the attendant.