Question 895968
You hike two thirds of the way to the top of a hill at a speed of 3.0 mi/h and run the final third at a speed of 6.0 mi/h. what is the average speed
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Let "x miles" be the distance up the hill.
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1st leg DATA:
distance = (2/3)x miles ; rate = 3 mph ; time = d/r = (2x/3)/3 = (2/9)x hrs
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2nd leg DATA
distance = (1/3)x miles ; rate = 6 mph ; time = d/r = (1/18)x hrs
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Average speed = (total distance)/(total time) = (x)/_{(1/18)+(4/18)]x}
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= (5/18) mph
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Cheers,
Stan H.