would Paul be able to claim that he as in the 100 percentile, if his exam score was based off of extra credit and the highest possible score of the exam was 90% without the extra credit points? What would Paul's ranking be then

Answer 1

First of all, the highest possible score on any test would be 100% of the points.

Need to know Paul's score and the range of scores to say whether he was in the 100th percentile.