I can't remember the exact make up of the mass calculation, but I will tell you this. There were four of us within 1/1000 of a point of each other at the end. That's a handfull of EPQ questions. Oh, and everything is curved which has created quite a bit of controversy in years past. If the number one guy has 100% average in academics, and the dead last guy has 97% average. The number one guy will get 100% of the 5 points or so that academics count for, and the dead last guy will get 85% of 5 points, even though he had a 97% average.
Good Luck.