Organizers of an Internet training session will charge participants $50 to attend. It costs $1,000 to reserve the room, hire the instructor, bring in the equipment, and advertise. Assume that the cost for printing course materials is $10 per student for the organizers if the enrollment for the session is less than 30 students. If the enrollment is 30 or more students a more powerful machine must be used and the course materials cost $20 per student. 

a) Develop an expression for the total cost to the organizers. 

b) How many students would have to attend for the company to break even? 

c) Graph both the cost and revenue functions on the grid below. Shade and label regions of loss and gain.