To find out how many students were on each bus, we first need to determine how many students traveled by bus.
Total students: 300
Students in cars: 12
So, the number of students who took the buses is: 300 - 12 = 288 students.
There are 6 buses, so to find the number of students on each bus, we divide the total number of students who took the buses by the number of buses:
288 students รท 6 buses = 48 students per bus.
Therefore, the answer is 48.