The first one can consist of three touchdowns for the first team and a feild goal for the second team. The second one would consist of two touchdowns and a field goal for the first team and a field goal and a two point conversion for the second team. They are both possible but 21-3 is more likley because it dont consist of a two point conversion which is rare to happen in the first place.
Note: The touchdown points were saying that the made the kick
