A phone company has two weekly plans to choose from. Plan A charges $31.45, plus 15.5 cents per minute. Plan B charges $5.20 plus 37 cents per minute

Question

A phone company has two weekly plans to choose from. Plan A charges an operating fee of $31.45, plus 15.5 cents per minute. Plan B charges an operating fee of $5.20, plus 37 cents per minute. Determine how you would decide on which plan would be best for you, and explain your reasoning

Answer 1

Let x = # min

A: 31.45 + .155x

B: 5.20 + 0.37x

The best way to solve this would be to graph it and look at the cost based on the number of minutes. Algebraically, I'll find when the two plans cost the same and talk about what the graphs look like

31.45 + .155x = 5.20 + 0.37x

26.25 = 0.215x

x = 122.1 min

Initially Plan A costs more (as the y-intercept ≈ $32 vs. $5), until you talk about 2 hrs (120/60 = 2) at that point both plans cost the same. If you talk more than 2 hrs Plan A is cheaper than Plan B. The best way to make a decision about which plan you'd like would be to consider the number of minutes you plan to talk each month.