1. Corinne has a cell phone plan that includes 200 minutes for phone calls and unlimited texting. An additional fee is charged for using more than 200 minutes for phone calls. The figure below is the graph of C = f(m), where C is the monthly cost after m minutes used. Part A What is the minimum monthly cost for Corinne's cell phone plan? Show or explain your work.

Part B What is the value of f(150). Explain its meaning in terms of the cell phone plan.

Part C For what mis f(m) = 55? Explain its meaning in terms of the cell phone plan.

Part D What is the cost per minute after Corinne uses her monthly allowance of 200 minutes? Show or explain your work.