Answer:
For average speed of 60 miles/hr: Time for the trip=25 hours and gasoline cost=$119.53.
For average speed of 75 miles/hr: Time for the trip=20 hours and gasoline cost=$153.
Step-by-step explanation:
Given that, the car averages 32 miles/gallon and 25 miles/gallon for the average speeds of 60 miles /hr and 75 miles/hr respectively.
As the trip is of 1500 miles, so the total distance to be covered is 1500 miles
![\text{Driving time}=\frac{\text{Total distance}}{\text{Average speed}}](https://tex.z-dn.net/?f=%5Ctext%7BDriving%20time%7D%3D%5Cfrac%7B%5Ctext%7BTotal%20distance%7D%7D%7B%5Ctext%7BAverage%20speed%7D%7D)
For average speed= 60 miles/hr,
Driving time=1500/60=25 hours.
At this speed for covering 32 miles, the car consumes 1 gallon of gasoline.
So, for covering 1 mile, the car consumes 1/32 gallon of gasoline
For covering 1500 miles, the car consumes 1500/32=46.875 gallons of gasoline.
So, the cost of gasoline = 46.875 x 2.55= $119.53
Similarly, for the average speed = 75 miles/hr,
Driving time=1500/75=20 hours.
Quantity of gasoline consumption=1500/25=60 gallons.
Cost opf gasoline= 60 x 2.55= $153.