The result of each written examination as to each applicant shall be certified to the commissioner by the examining board or majority thereof as satisfactory or unsatisfactory. If unsatisfactory, the applicant may upon his written request made within 20 days from notice of the result have a hearing before the examining board or a member thereof to inquire into the reasons for the certified result. Within 20 days thereafter the examining board or the majority thereof shall affirm or alter the certified result.