There is a TOTAL of 500 questions in part II.
In day 1 there are 400Q which which are randomly tested.
In day 2 there are 100Q case based.
The results candidates received are broken down to different disciplines which are added up to 500Q. This includes 400 random questions and 100 case based questions.
The candidates are also informed of how many questions they scored out of 100 case based questions.
To calculate your raw score just add what you get in all disciplines. This should not exceed 500. IGNORE the case base portion. 100 case based questions are already dissected and assigned to all disciplines.
Hope this helps in determining your raw score and not creating any more confusion.