Since the students were divided into 10 teams, and each team has 12 students, the total number of students is:
So the total number of students is 120.
Then, these students were divided into teams where each team has 30 students.
To find the number of teams with 30 students, we just need to divide the total number of students by the number of students in each team:
Therefore 4 teams can be made with 30 students in each team.