Answer:
Since the number of buses needed to transport the members on each trip is a function of the number of members who went on each trip, then the independent variable(x) of the function is the number of members who went on each trip and the dependent variable (y) is the number needed. Then each point that represent the function has the form (x,y).
Then, the domain of the function is the set of values that can take the independent variable. In this case, x can take the values , that is, A is the domain for this situation.