SOLUTION: Starting at home, Christopher traveled uphill to the grocery store for 90 minutes at just 4 mph. He then traveled back home along the same path downhill at a speed of 12 mph.
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Question 961041: Starting at home, Christopher traveled uphill to the grocery store for 90 minutes at just 4 mph. He then traveled back home along the same path downhill at a speed of 12 mph.
What is his average speed for the entire trip from home to the grocery store and back? Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website! Starting at home, Christopher traveled uphill to the grocery store for 90 minutes at just 4 mph. He then traveled back home along the same path downhill at a speed of 12 mph.
What is his average speed for the entire trip from home to the grocery store and back?
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90 min=90/60=1.5 hr
distance from home to the grocery store=travel time*speed=(1.5)*4=6 mi
travel time from grocery store to home=distance/speed=6/12=1/2 hr
average speed=total distance/total travel time=12/2=6 mph
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