Question

Gas mileage actually varies slightly with the driving speed of a car (as well as with highway vs. city driving). Suppose your car averages 28 miles per gallon on the highway if your average speed is 51 miles per hour, and it averages 17 miles per gallon on the highway if your average speed is 68 miles per hour.

a. What is the driving time for a 1700-mile trip if you drive at a speed of 51 miles per hour? What is the driving time at 68 miles per hour?

b. Assume a gasoline price of $3.39 per gallon. What is the gasoline cost for a 1700-mile trip if you drive at an average speed of 51 miles per hour? What is the gasoline cost at 68 miles per hour?

Answer 1

The driving time for a 1700-mile trip at a speed of 51 miles per hour is 33.33 hours, while the driving time at 68 miles per hour is 25 hours. The gasoline cost for a 1700-mile trip at an average speed of 51 miles per hour is $205.85, and the gasoline cost at 68 miles per hour is $339.

Step-by-step explanation:

a. To calculate the driving time for a 1700-mile trip at a speed of 51 miles per hour, divide the distance by the speed: 1700 miles / 51 miles per hour = 33.33 hours. To calculate the driving time at 68 miles per hour, divide the distance by the speed: 1700 miles / 68 miles per hour = 25 hours.

b. To calculate the gasoline cost for a 1700-mile trip at an average speed of 51 miles per hour, multiply the distance by the average gas mileage: 1700 miles / 28 miles per gallon = 60.71 gallons. Multiply the gallons by the gasoline price: 60.71 gallons * $3.39 per gallon = $205.85. To calculate the gasoline cost at 68 miles per hour, follow the same steps: 1700 miles / 17 miles per gallon = 100 gallons. Multiply the gallons by the gasoline price: 100 gallons * $3.39 per gallon = $339.