SOLUTION: you drive to the beach at a rate of 120 kilometers per hour. On the return trip you drive at a rate of 60 kilometers per hour. What is your average speed for the entire trip?
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Question 564711: you drive to the beach at a rate of 120 kilometers per hour. On the return trip you drive at a rate of 60 kilometers per hour. What is your average speed for the entire trip? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! you drive to the beach at a rate of 120 kilometers per hour.
On the return trip you drive at a rate of 60 kilometers per hour.
What is your average speed for the entire trip?
:
Let a = the average speed for the whole trip
let d = the one-way distance of the trip
:
Write time equation, time = dist/speed
:
To time + return time = total time + =
Multiply by 120a
120a* + 120a* = 120a*
cancel the denominators
ad + 2ad = 120(2d)
3ad = 240d
Divide both sides by d
3a = 240
a = 240/3
a = 80 km/hr is the av speed for the round trip
