SOLUTION: Frank drove 100 mi. For the first 55 mi. he averaged 50 mph and for the last 45 mi he averaged 30 mph. What was his average speed for the entire trip?
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Question 285184: Frank drove 100 mi. For the first 55 mi. he averaged 50 mph and for the last 45 mi he averaged 30 mph. What was his average speed for the entire trip? Found 2 solutions by stanbon, Deina:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Frank drove 100 mi. For the first 55 mi. he averaged 50 mph and for the last 45 mi he averaged 30 mph. What was his average speed for the entire trip?
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Average speed = total distance/total time
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First segment DATA:
distance = 55 mi ; rate = 50 mph ; time = d/r = 11/10 = 1.1 hr
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Second segment DATA:
distance = 45 mi ; rate = 30 mph ; time = d/r = 45/30 = 1.5 hr
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Equation:
Average = 100/(1.1+1.5) = 100/2.6 = 38.46 mph
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Cheers,
Stan H.
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