SOLUTION: Starting at home, Christopher traveled uphill to the hardware store for 50 minutes at just 6 mph. He then traveled back home along the same path downhill at a speed of 12 mph.
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Question 946840: Starting at home, Christopher traveled uphill to the hardware store for 50 minutes at just 6 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 hardware store and back?
You can put this solution on YOUR website! Starting at home, Christopher traveled uphill to the hardware store for 50 minutes at just 6 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 hardware store and back?
:
let a = his average speed of the trip
let d = the one-way distance
:
Write a time equation; time = dist/speed
Uphill time + downhill time = total time + =
Multiply equation by 12a
12a* + 12* = 12a*
Cancel the denominators
2ad + ad = 24d
3ad = 24d
divide both sides by d
3a = 24
a = 24/3
a = 8 mph is the av speed of the round trip
