In the case of the missing dollar paradox there is no missing dollar. The way that the structure is set up is to make the reader think there is a missing dollar but in actuality all the money is accounted for. At the point where the paradox states that the twenty-seven plus two is twenty-nine is correct but your not supposed to be adding the two dollars that the waiter took but the three dollars that was returned to them. The two dollars that the waiter took is already included in the twenty-seven dollars the ladies know to be the bill. By adding the three dollars returned to the women you end with the original thirty.