This 2-hour, 100 multiple choice question exam is the computer portion of the CNA State exam. A 70 percent or greater score is required to be eligible for the Iowa Direct Care Workers Registry. A separate registration is needed for the skills exam. If you are unable to pass both exams after 3 attempts for each test, the Nurse Aide Training course must be taken/re-taken prior to re-testing. Registration closes at 12:00 PM on the Thursday prior to the start date.