SOLUTION: Dustin drives 5 mph faster than Kelly. If he leaves town one hour after Kelly and they travel in opposite directions, they will have driven equal distances after Dustin has travel

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Question 700776: Dustin drives 5 mph faster than Kelly. If he leaves town one hour after Kelly and they travel in opposite directions, they will have driven equal distances after Dustin has traveled seven hours. How far apart are they?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Dustin drives 5 mph faster than Kelly.
If he leaves town one hour after Kelly and they travel in opposite directions, they will have driven equal distances after Dustin has traveled seven hours.
How far apart are they?
:
Let s = K's speed
then
(s+5) = D's speed
:
K travels 8 hrs
:
Write a distance equation; dist = speed * time
8s = 7(s+5)
8s = 7s + 35
8s - 7s = 35
s = 35 mph is K's speed
:
Find the distance he traveled in 8 hrs
8 * 35 = 280 mi
Find D's distance, they should be the same
7 * 40 = 280 mi
:
They would be 2(280) 560 mi apart