Question 57698:  Because of rising gas prices, Mr. Rohdie is considering buying a hybrid car.  His choice boils down to buying either a Toyota Prius (a hybrid) for $24,500 or a Toyota Camry (not a hybrid) for $20,250.  He wants you to figure out for him how long it will take before the Prius saves him money, despite the fact that it costs $4,250 more to buy originally.  Here’s what you need to know: 1.) for the Prius he does not have to pay state sales tax (6%), but for the Camry he does;  2.) the Prius averages 50 miles per gallon (mpg) of gasoline, while the Camry averages 24 mpg; and 3.)  Assume that gasoline will cost an average of $2.75 per gallon for the length of time Mr. Rohdie will own his new car and that he will average 15,000 miles of driving per year. 
 
 
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! Prius cost for "x" years of driving: 
Cost = 24500+(15000/50)*2.75x 
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Carmy cost fo "x" years of driving: 
Cost = 1.06*20250+(5000/24)*2.75x 
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Graphing these with a TI-83 I find the 
two lines intersect at approximately 3.39 years; 
after that the Prius cost is below the Camry cost. 
Cheers, 
Stan H. 
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