Posted by Courtney on .
A truck driver traveled at an average speed of 55 miles per hour on a 200 mile trip to pick up a load of freight. On the return trip(with the truck fully loaded), the average speed was 40miles per hour. What was the average speed for the round trip?

College Algebra 
Reiny,
Average speed = total distance traveled/total time taken
time for first leg of trip =200/55 hrs
time for second leg of trip = 200/40 hours
so average speed = 400/(200/55 + 200/40)
=46.3 mph