A man travels for 6 hours at a rate of 50 miles per hour. His return trip takes him 7 1/2 hours. What is his average speed for the whole trip?
Multiply 6 hours times the rate of 50 miles per hour to get the total miles he traveled there. Which it was 300 miles to get there. It must have taken 300 miles to get back also. So divide distance (300) by time (7.5) to get 40 mph was the speed coming back. Now find the average of the two speeds ( 50+40=90 divded by 2) THE ANSWER IS 45 MPH FOR THE AVERAGE SPEED! (: