Question 522681: A truck driver began driving at 8 am,drove 570 miles,and arrived at his destination at 6 pm. His stops along the route added up to exactly 1 hour. While he was driving, he averaged 65 mph for the first part of the trip and 60 mph for the rest of the trip. How long did he travel at each rate?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! A truck driver began driving at 8 am,drove 570 miles,and arrived at his destination at 6 pm.
His stops along the route added up to exactly 1 hour.
While he was driving, he averaged 65 mph for the first part of the trip and 60 mph for the rest of the trip.
How long did he travel at each rate?
:
From the information given, we know the trip took 10 hrs
Stops added up to 1 hr, so travel time = 9 hrs
:
Let t = travel time at 65 mph
then
(9-t) = travel time at 60 mph
:
Write a distance equation, dist = speed * time
65t + 60(9-t) = 570
65t + 540 - 60t = 570
65t - 60t = 570 - 540
5t = 30
t = 30/5
t = 6 hrs at 65 mph
then
9-6 = 3 hrs at 60 mph
:
:
Check this by finding the dist at each speed
65(6) = 390
60(3) = 180
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total = 570
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