It takes Bob the same amount of time to travel 600 miles as

It takes Bob the same amount of time to travel 600 miles as it takes Kurt to travel 450 miles. If Bob drives 20mph faster than Kurt, how fast does each person drive?
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Solution

Distance = (Rate)(Time) [use the distance formula]
Bob: 600=(r+20)t
Solve for t: 600/(r+20)=t
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Kurt: 450=rt
Solve for t:450/r=t
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Bob\'s time = Kurt\'s time
So, 600/(r+20)=450/r[Solve for r]
(600)(r)=(r+20)(450)
600r=450r+9000
600r-450r=9000
150r=9000
r=9000/150
r=60 miles per hour
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Kurt=r=60 miles per hour
Bob: r+20=60+20=80 miles per hour