I've got an exam that draws 40 questions from 4 question banks, then goes to a result slide. It's a minor issue: when the user clicks Submit for the last question, another question slide appears before the Results slide is generated. It only lasts half a second, but it looks amateurish. :-)
I'm using variables in the slide titles: Exam %QuestionNumber% of %TotalQuestions%. When the user clicks Submit, QuestionNumber increases by 1. In the Triggers panel, I have it occur before the "submit interaction" trigger. Otherwise, the Question Number won't change. Here's a screenshot.