Question 1008835
Tim drove halfway Indianapolis at 60 mi/h and the rest of the way at 80 mi/h. What was his average speed for the whole trip?
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For a round-trip, or trip with 2 parts of equal distance:
Avg = 2*60*80/(60+80) = 9600/140
= 480/7 mi/hr
=~ 68.57 mi/hr
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It's not 70 because more time is spent at 60 mi/hr.