Question 1031625: my journey to work is at 10mph in heavy traffic, my journey home is at 30mph with no traffic. what is my average speed to work and back? Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! my journey to work is at 10mph in heavy traffic, my journey home is at 30mph with no traffic. what is my average speed to work and back?
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Avg of the round trip is
2*10*30/(10 + 30) = 600/40
Avg = 15 mi/hr
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The formula is similar to parallel resistors and parallel work.
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One way distance = d
Avg speed = (d/10 + d/30)/2
You can solve that and get the same answer.
Avg = 40d/600 = d/15
--> Avg = 15 mi/hr
