Carla's car has a higher fuel efficiency (36 mpg) compared to Stanley's car (30 mpg).
The slope of a line in a mileage versus gasoline consumption graph represents the fuel efficiency of a car. The slope is calculated as the change in mileage divided by the change in gasoline consumption.
For Stanley's car:
Initial mileage = 840 miles
Final mileage = 1,200 miles
Gasoline used = 12 gallons
The change in mileage = Final mileage - Initial mileage = 1,200 miles - 840 miles = 360 miles
The change in gasoline consumption = Gasoline used = 12 gallons
Slope for Stanley's car = Change in mileage / Change in gasoline consumption
= 360 miles / 12 gallons
= 30 miles per gallon (mpg)
For Carla's car:
Initial mileage is the same (840 miles)
Final mileage is the same (1,200 miles)
Gasoline used = 10 gallons
The change in mileage = Final mileage - Initial mileage = 1,200 miles - 840 miles = 360 miles
The change in gasoline consumption = Gasoline used = 10 gallons
Slope for Carla's car = Change in mileage / Change in gasoline consumption
= 360 miles / 10 gallons
= 36 miles per gallon (mpg)
Comparing the slopes:
Carla's car has a higher fuel efficiency (36 mpg) compared to Stanley's car (30 mpg). This means Carla's car travels more miles per gallon of gasoline consumed, indicating better fuel efficiency.
Question
Stanley drove his car on a business trip when he left, the mileage was 840 miles, and when he returned, the mileage was 1,200 miles. The car used 12 gallons of gasoline for this trip.
Carla made the same trip as Stanley, but her car used only 10 gallons of gasoline. How do the slopes for Stanley's and Carla's cars compare?