How do you calculate MRS, MUX AND MUY AND THE REST?

a) (8 Points) A consumer is considering choosing a calling plan for her cell phone. The plan has a fixed monthly fee of $40, and it gives 200 free minutes per month and charges $0.1 for each additional minute. The consumer has a monthly income of $100, and she spend it on cell phone and another composite good y, where Py =$1. Her utility function y 2 Find her optimal consumption bundle. Graph your solution on a diagram - including the budget line and a representative indifference curve