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Question 100077: Students are traveling in two cars to a football game 135 miles away. The first car leaves on time and travels at an average speed of 45 miles per hour. The second car starts 30 minutes later and travels at an average speed of 55 miles per hour. How long will it take the second car to catch up to the first car? Will the second car catch up to the first car before the frst car arrives at the game?
So far I have tried this:
t= 1st car's time when 2nd car catches up,
2nd car left 30 minutes later, so its 1/2 hour therefore t-(1/2)
then I tried setting up an equation
1st car distance= 2nd car distance....
but it doesnt seem to work from here! maybe there's something wrong with my approach to the question. Thank you for your help!
Answer by scott8148(6628)   (Show Source):
You can put this solution on YOUR website! the first car has a 22.5mi head start -- 45mph*.5h=22.5mi
the second car goes 10mph faster so it will take 2.25h to catch up -- 22.5mi/10 mph=2.25h
at this point, the first car has been driving 2.75h
since it takes 3h to get to the game (135mi/45mph), the second car catches up before the first car arrives
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