Mathematics may be actually useful in making some decisions. Deciding on which company to use when renting a car or getting a phone service is a classic example. Let's use what we know about the calculator to solve this problem:

Can you help me with a car rental decision? I am doing a professional development for a district in Utah next week. Even though I'll only be there one day, it's quite a ride from the airport to the school where I am presenting. I want to use one of the three car rental companies I have had good experiences with before. The offers, shown below, do not include gas and taxes since they are the same for each plan.

• Hertz charges $73 for the day, with unlimited mileage.
  
  
• Alamo charges $50 each day and 20 cents per mile.
  
  
• Budget has a special promotion which gives you the car for FREE, but charges 50 cents per mile driven.

Which plan will cost me the least?