Self-taught exams are generally twice a year (4 times in some provinces), and you can apply for up to 4 subjects at a time. Different schools, different majors, the number of subjects to be tested is different, generally around 15 subjects. So the time to pass the self-study exam is generally 2-2.5 years.

It took two and a half years to be admitted to the undergraduate course of mechatronics, but it was in Changsha.