6 A concept car that will get 100 miles per gallon and carry four persons would have a carbon-fiber and aluminum composite frame with a 900 cc threecylinder turbodiesel/electric hybrid power plant. The extra cost of these technologies is estimated to be $11,000. (a) If gasoline savings over a comparable conventional car would be $900 in year one, increasing by 10% each year, what is the present worth of the savings over a 10-year period at an interest rate of 8% per year