If you're actually in competition with some other people for the job, and the person who gets the highest score on the exam will get the job, then I don't see why you can't say it.
It sounds like a rather odd recruitment process to me though. Normally, we take our exams at school/college/university and then apply for a job which we get (or don't get) based on our qualifications and how well we do at the interview. Some jobs require you to do some kind of aptitude or competency test to see how well you deal with certain situations but sitting a whole exam alongside other people to get a job seems rather harsh!