Problem 9: Consider the following multi-part tariff offered by a cellphone services company. To subscribe, you need to pay 10 dollars. If you talk at most 200 minutes, you pay 20 cents per minute. For any extra minutes from 200 to 300, you pay 10 cents. Minutes above 300 are free. The tariff is shown in the table below. Fixed fee 10 dollars First 200 minutes 20 cents per minute (additional) Minutes 200 to 300 10 cents per minute (additional) Minutes 300 and above 0 cents per minute (additional) (a) Draw a graph that shows how much money each consumer pays, given the number minutes used. (b) As we discussed in class, the seller can instead offer the consumers the option to choose between three different two-part tariffs. What are those two-part tariffs? (c) Assume that there are three consumers. Consumer 1 wants to talk for 50 minutes, consumer 2 for 250 minutes, and consumer 3 for 400 minutes. What is the seller's revenue