10*. A student passed 31 exams over 5 years of study. In each subsequent year, he passed more exams than in the previous year. In the fifth year, the number of exams was three times that of the first year. How many exams were there in the fourth year?

Could the student have had only one exam in the first year? Check and make a conclusion. Could he have started with two exams? Perform the check. What about three exams? Perform the calculations and make a conclusion. Could the student have had 4, 5, or more exams in the first year? Why?