2. The first digit of the number 3 is the last two digits of the class, such as the student number. For example, 2 15 is the student of Class 2 15.
(1) Judging from 107 and 2 10 and 328, it should be 1, category 7, category 2, 10, category 3 and category 28.
(2) If you want to look at numbers, boys and girls can add another 0 or 1 to the numbers, with boys starting with 0 and girls starting with 1.
For example: 12 15, which means that Class 2 on 15 is a girl.