Answer:
---- Band A
--- Band B
Explanation:
Given
Band A:
per student
Band B:
per student
Required
Write an equation for the system?
For band A, the given charges is irrespective of number of students.
So, the total cost y is:

For band B, the total y is calculated as thus:
y = Base Charges + Rate * Number of students (x)


So, the charges for the bands are:
---- Band A
--- Band B