Northeastern: Save yourself embarrassment. Do not give this clown a degree. I understand you had to admit him to keep the federal money coming in but he will only cause you much bad publicity in the future.
First of all, he doesn’t know the difference between reverse and Inverse of a fraction. 5/3 is not the reverse of 3/5.
Second, as you are aware, but apparently your doctoral student isn’t, the 3/5 rule is contained in the 13th Amendment, not in the Constitution itself.
It's in Art. 1 §2: "... and excluding Indians not taxed, three fifths of all other Persons."