Q:

Gas mileage actually varies slightly with the driving speed of a car​ (as well as with highway vs. city​ driving). Suppose your car averages 33 miles per gallon on the highway if your average speed is 48 miles per​ hour, and it averages 29 miles per gallon on the highway if your average speed is 67 miles per hour. a. What is the driving time for a 2600​-mile trip if you drive at an average speed of 48 miles per​ hour? What is the driving time at 67 miles per​ hour?The driving time at 48 miles per hour is ___ hours.​(Type an integer or decimal rounded to two decimal places as​ needed.)The driving time is at 67 miles per hour is __hours.​(Round to two decimal places as​ needed.)b. Assume a gasoline price of ​$3.05 per gallon. What is the gasoline cost for a 2600​-mile trip if you drive at an average speed of 48 miles per​ hour? What is the gasoline cost at 67 miles per​ hour?The gasoline cost at 48 miles per hour is ​$:​(Round to two decimal places as​ needed.)The gasoline cost at 67 miles per hour is $​:​(Round to two decimal places as​ needed.)

Accepted Solution

A:
Answer:a)First part: "The driving time at 48 miles per hour is 54.17 hours."Second part: "The driving time at 67 miles per hour is 38.81 hours."b)First part:  "The gasoline cost at 48 miles per hour is ​$240.30"Second part: "The gasoline cost at 67 miles per hour is $​273.45"Step-by-step explanation:a)We use the equation  [tex]D=RT[/tex]  to solve this. Where D is the distance, R is the rate (speed), and T is the time.First part:The distance is 2600 miles (D) and the rate (R) is 48 mph, so time is:[tex]D=RT\\2600=(48)T\\T=\frac{2600}{48}\\T=54.17[/tex]"The driving time at 48 miles per hour is 54.17 hours."Second part:The distance is 2600 miles (D) and the rate (R) is 67 mph, so time is:[tex]D=RT\\2600=(67)T\\T=\frac{2600}{67}\\T=38.81[/tex]"The driving time at 67 miles per hour is 38.81 hours."b)First part:At 48mph, the fuel consumption is 33 miles per gallon. The number of gallons needed is 2600 divided by 33:Number of Gallons = [tex]\frac{2600}{33}=78.79[/tex]Total cost @ 3.05 per gallon = 78.79*3.05=$240.30"The gasoline cost at 48 miles per hour is ​$240.30"Second part:At 67 mph, the fuel consumption is 29 miles per gallon. The number of gallons needed is 2600 divided by 29:Number of Gallons = [tex]\frac{2600}{29}=89.66[/tex]Total cost @ 3.05 per gallon = 89.66*3.05=$273.45"The gasoline cost at 67 miles per hour is $​273.45"