Question 64909
At the same time Kris leaves Washington D.C.,for Detroit,Michigan,Amy leaves Detroit for Washington D.C. The distance between the cites is 510 miles.Amy's average speed is 5 miles per hour faster than Kris's. How fast is Kris's average speed if they pass each other in 6 hours?
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Kris DATA:
time = 6 hrs ; distance = x miles ; rate= d/r = x/6 mph
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Amy DATA:
time = 6 hrs ; distance = "510-x" miles ; rate = d/r = (510-x)/6
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EQUATION:
Amy rate - Rick rate = 5 mph
(510-x)/6 - x/6 = 5
510-x - x = 30
-2x=-480
x=240 miles (Kris's distance)
Kris's rate = 240/6 = 40 mph
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Cheers,
Stan H.