Answer:
<u>The semi-trailer truck has the fastest average speed</u>
Step-by-step explanation:
Let's recall that the formula of the average speed is:
Average speed = Distance/Speed
Now, we can calculate the average speed for each class of vehicle, as follows:
Flatbed truck average speed = 144/5 = 28.8 miles per hour
<u>Semi-trailer truck average speed = 327/4 = 81.75 miles per hour</u>
Tanker truck average speed = 589/15 = 39.27 miles per hour
Which truck has the fastest average speed?
<u>The semi-trailer truck has the fastest average speed</u>