Hmm. I may have used a wrong term.
My students have several ways of passing the course. The recommended, most painless and preferred way is to do well enough in the midterm exams. Failing that they can also try to pass the course with a single final exam. Some do this because they couldn't make it to one of the midterms (family reasons, health, hangover, travel, whatever). Some take the final exam simply because they failed to do well enough in the midterms. They are given 3-4 attempts. This time the first opportunity will be next Monday. The other opportunities are spread over the span of 9 months on selected dates, when students can sign up to take one of several exams offered by the math department. Our system is, perhaps, more permissive than what you have in the US or UK. As an undergrad I took advantage of this flexibility. As I had a heavy course load, I had no choice but to spread the finals all over the academic year.
Anyway, close to 90% of my students passed by doing well enough in the midterms, so most of my grading is done. Some of them may try their luck in a final in order to improve their grade, so it is hard to tell how many will show up. Probably not too many.
Edit: That guy seems to have a flexible attitude - I did LOL at his Q&A section! I go the extra mile and do organize an extra office hour for those students who have retaken the exam at least twice, failed, but have shown some effort (say, passing grade is something like 50%, and they have scores in the forties). That actually helps, because often I can see that they struggle, because they have not grasped some high school level material, and pay the price in several problems. So a tailored review session combined with going through their past mistakes may not be a total waste of my (and their) time.
Of course, some of them really shouldn't be studying math at this level, but it is not my job to tell them that. I can give a hint though.