SOLUTION: A driver drives 20 miles at 20mi/hour. How fast must the driver go for the next 20 miles to bring the average speed for the whole trip up to 30mi/hour? What is the average speed he

Question 604276: A driver drives 20 miles at 20mi/hour. How fast must the driver go for the next 20 miles to bring the average speed for the whole trip up to 30mi/hour? What is the average speed he cannot go to recover time?
I know that he has to go an average of 40mi/hour to get there using the equation Average speed =total distance/ total time
Answer by flame8855(424) (Show Source): You can put this solution on YOUR website!
average speed = 30 mi/hour
average speed= total distance /total time
30= 40mi/(x+1)
x= 1/3 hour
speed = distance /time
speed = 20/1/3 = 60 miles /hour
a speed less than 60 he will not recover

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