Final answer:
To find the average speed, convert minutes to hours, sum the hours, and then divide the distance by the total time. The car must travel at an average speed of approximately 56 miles per hour to cover 322 miles in 5 hours and 45 minutes.
Step-by-step explanation:
To calculate the average speed of a car that travels 322 miles in 5 hours and 45 minutes, we need to convert the time to hours and then divide the distance by the total time in hours.
First, convert 45 minutes to hours: 45 minutes ÷ 60 minutes/hour = 0.75 hours.
Now, add this to the 5 hours to get the total time: 5 hours + 0.75 hours = 5.75 hours.
Next, divide the total distance traveled by the total time in hours to find the average speed:
322 miles ÷ 5.75 hours = 56 miles per hour (rounded to the nearest whole number).
This means the car must travel at an average speed of approximately 56 miles per hour to cover 322 miles in 5 hours and 45 minutes.