Final answer:
To estimate the gallons of gas used by Karl, divide the total miles driven, 617.3, by the car's fuel efficiency, 41 mpg, which equals approximately 15 gallons. This is the best estimate for the amount of gasoline used.
Step-by-step explanation:
The student is asking for the best estimate of how many gallons of gas were used for a trip of 617.3 miles, given that the car's fuel efficiency is 41 miles per gallon. To estimate the amount of gasoline used, you would divide the total number of miles driven by the miles per gallon efficiency of the car. Therefore:
Total miles driven (617.3 miles) ÷ Miles per gallon (41 mpg) = Gallons of gas used
617.3 ÷ 41 = 15.06
Since we are looking for the best estimate, you would round this number to the nearest whole number, which gives us 15 gallons. Thus, the best estimate of the number of gallons of gas Karl used is 15 gallons, which corresponds to option A).