Seventeen are the teachers among Carats

This is a teacher-themed series [I don't know much about the teachers] 30 - Seungchul, Jeonghan, Jisoo 29 - Junhwi, Soonyoung, Wonwoo, Jihoon 27 - Mingyu, Seokmin, Myungho 26 - Seungkwan, Hansol 25 - Chan 1st Grade - Jihoon (1), Chan (2), Jeonghan (3) 2nd Grade - Junhwi (1), Seokmin (2) 3rd Grade - Seungchul (1), Seungkwan (2) Seungchul - Physical Education (Overall) / Jeonghan - Math (1.2) / Jisoo - English (3) / Junhwi - Chinese (2.3) / Soonyoung - Health (Overall) / Wonwoo - Korean (2.3) /