Suppose we know the relationship d=500025p describes what happens to demand (d) as price (p) varies. Here, price can vary between $15 and $45. (17pts) a. How many units can be sold at the $20 price? Find the value for revenue at this price. b. How many units can be sold at the $40 price? Find the value for revenue at this price. c. Write the expression for total revenue. 9. A university schedules a one-week training course based on anticipated enrollment. The variable cost is about $400 pe student, laboratories, student services, and allocated overhead for a class is $5000. If students pay $600 to enroll in the course, how large would enrollment have to be for the university to break even? (10 pts )