bridge

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bridge

by gmat009 » Mon Nov 24, 2008 6:03 pm
If car X followed car Y across a certain bridge that is 1/2 mile long, how many seconds did it take car X to travel across the bridge?
(1) Car X drove onto the bridge exactly 3 seconds after car Y drove onto the bridge and drove off the bridge exactly 2 seconds after car Y drove
off the bridge.
(2) Car Y traveled across the bridge at a constant speed of 30 miles per hour.

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by cramya » Mon Nov 24, 2008 6:38 pm
I am getting C).

Whats the oa?


From both statements u can get the time travlled by th leading Y CAR.The x car would have taken 1 sec less since it started 3 seconds behind but finished only 2 seconds behind (gained a sec in the process)

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by pbanavara » Mon Nov 24, 2008 6:57 pm
I think the OA is C:

pretty simple : Option 1 tells that the car x gained over car y by one second - but we don't know the speed of car y so can't obtain the speed of car x

Option 2 - gives the speed of car y so that should do.

So both should be sufficient. If this proves wrong - I'll have to take a serious look at my math skills :)

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by vittalgmat » Mon Nov 24, 2008 10:48 pm
I get C as well.
Here is my reasoning: Y is travels at a constant speed of 30 mph. so we can find out the time taken . say x seconds. From statement 1,
we get X entered 3 sec later, and left 2 sec later than Y. So we can figure out the time for x.

thanks

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by orel » Tue Nov 25, 2008 12:15 am
another vote for C