A friend of yours is considering two cell phone service providers. Provider A charges $120 per month for the service regardless of the number of phone calls made. Provider B does not have a fixed service fee but instead charges $1 per minute for calls. Your friend's monthly demand for minutes of calling is given by the equation Q^D = 150 - 50P, where P is the price of a minute (please note that ^D denotes an exponent, so it's Q to the D power).

A. With each provider, what is the cost to your friend of an extra minute on the phone?

A friend of yours is considering two cell phone service providers. Provider A charges $120 per month for the service regardless of the number of phone calls made. Provider B does not have a fixed service fee but instead charges $1 per minute for calls. Your friend's monthly demand for minutes of calling is given by the equation Q^D = 150 - 50P, where P is the price of a minute (please note that ^D denotes an exponent, so it's Q to the D power).

B. How much consumer surplus would he/she obtain with each provider? (Hint: Graph the demand curve and recall the formula for the area of a triangle).