John enjoys ordering out for pizza and renting movies online. He makes $30 each week at a part-time job. If movies cost $2 per rental, and pizza costs $7.50 per slice, graph John's budget constraint. Then, illustrate the effects of each of the following events:
a. John's mother finds a coupon good for one free pizza, and gives it to John.
b. The company that John rents movies from sponsors a holiday week promotion: Rent the first five movies at regular price; and all movies after the fifth are half-off.
c. John's favorite pizza place increases the price of pizza from $7.50 to $10.