The hotel bill
Three people check into a hotel room. The bill is $30 so they each pay $10. After they go to the room, the hotel's cashier realizes that the bill should have only been $25. So he gives $5 to the bellhop and tells him to return the money to the guests. The bellhop notices that $5 can't be split evenly between the three guests, so he keeps $2 for himself and then gives the other $3 to the guests.
Now the guests, with their dollars back, have each paid $9 for a total of $27. And the bellhop has pocketed $2. So there is $27 + $2 = $29 accounted for. But the guests originally paid $30. What happened to the other dollar?
Are you doing the math correctly?
$27.00 + $2.00 is not the correct math! The money the guests paid ($9.00 each) includes part of the $2.00 given to the bellhop.
Do the math as such: They paid 9.00 each which is $27.00. They let the bellhop keep $2.00. $27 - $2 = 25, what they paid for the hotel room!