Three men go to a hotel. The man behind the desk said the room is $30. Each man paid $10 and went to the room.
A while later the man behind the desk realized the room was only $25. He sent the bellboy to the guests’ room to return $5.
On the way the bell boy could not figure out how to split $5 evenly between the three men. The bellboy decided to keep $2 for himself, giving $1 to each of the three men.
This meant that the three men each paid $9 for the room, which is a total of $27. Adding the $27 that the men paid plus the $2 the bellboy kept adds to $29.
Where is the other dollar?
Answer
What you’ve got to ask yourself is: If the men paid 27, and the boy took 2 from that, why in the WORLD are you ADDING those two numbers instead of SUBTRACTING them? 27 MINUS 2 is 25, which is the total amount paid. 27 PLUS 2 is completely meaningless addition problem.
The thing that fools you into thinking it’s a meaningful problem is the fact that the answer is close to 30, so you think it should add up to that. But there’s no reason for that addition to add up to anything meaningful, because addition is not a meaningful thing to do with those two numbers in the context of the problem.
Let me put it this way. If I gave you twenty seven apples, and someone took two away from you, would you then have 29? Of COURSE NOT! But that’s exactly what the problem writer is trying to get you believe!