Model Management and Extreme Makeover In the model-management industry, firms supply human models for advertisements. Models vary in skin color, which is measured on a line of unit length. Skin color can be modified with makeup, and the makeup costs are incurred by the firm. Each firm enters the market at an address on the color line, and each firm manages two models. Suppose the cost of an extreme makeover (the cost of going from one end of the color line to the other) is $90. Illustrate the determination of makeup cost in (i) a city with 4 models (2 firms) and (ii) a city with 6 models (3 firms), including values for the makeup cost per model.