Jocelyn is pregnant and so she needs to eat at least 500 more calories a day than usual. When buying groceries one day with a budget of $15 for the extra food, she buys bananas that have 90 calories each and chocolate granola bars that have 150 calories each. The bananas cost $0.35 each and the granola bars cost $2.50 each.

a. Write a system of inequalities to model this situation.
b. Produce a presentation quality graph of the system and its solution.
c. Could she buy 5 bananas and 6 granola bars? Why or why not?