Variable costs, fixed costs, total costs. Bridget Ashton is getting ready to open a small restaurant. She is on a tight budget and must choose between the following long distance phone plans:
Plan A: Pay 10 cents per minute of long distance calling.
Plan B: Pay a fixed monthly fee of $15 for up to 240 long distance minutes, and 8 cents per minute thereafter (if she uses fewer than 240 minutes in any month, she still pays $15 for the month).
Plan C: Pay a fixed monthly fee of $22 for up to 510 long distance minutes and 5 cents per minute thereafter (if she uses fewer than 510 minutes, she still pays $22 for the month).
1. Draw a graph of the total monthly costs of the three plans for different levels of monthly long distance calling.
2. Which plan should Ashton choose if she expects to make 100 minutes of long distance calls? 240 minutes? 540 minutes?