POTW #18 Click here to print problem or scroll down to read problem. Then play video solution below. Click here to view video solution on YouTube. This problem is another winner of the student POTW video solution contest. Three guys stay in a single hotel room together, and the cost for the room is $30. Each man pays $10. Then, the manager remembered the $5 discount because of the construction. The manager sends a bellboy with $5. The men each keep $1, and give the bellboy $2. So, they all pay $9. 9 x 3 = 27, and the bellboy kept $2. $27 + $2 = $29. Where did the last dollar go?