SOLUTION: A car went 4 miles up a hill at 10 miles per hour and back down the same hill 20 miles per hour. What was the average speed for the round trip?

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Question 162810: A car went 4 miles up a hill at 10 miles per hour and back down the same hill 20 miles per hour. What was the average speed for the round trip?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
D=RT OR D/R=T
4/10+4/20=.4+.2=.6 IS THE TIME FOR THE TOTAL TRIP.
8/.6=13.33 MPH IS THE AVERAGE SPEED.