Latanya likes to talk on the telephone.

Latanya likes to talk on the telephone. We can represent her preferences with the utility function U(B, J) = 18B + 20J, where B and J are minutes of conversation per month with Bill and Jackie, respectively. If Latanya plans to use the phone for one hour to talk with only one person, with whom would she rather speak? Why? What is the formula for her indifference curves? Plot a few of those curves.