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Carla
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Post subject: Online Word Problems #9  Posted: Wed Apr 18, 2007 7:46 pm |
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Online Question Bank : Word Problems : #9
This problem asked about the time scientists predicted it would take for the animal to become extinct. I am hesitant to go with answer choice E and found this problem challenging. I would just like to go over it for some more clarification of the solution.
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Guest
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Post subject: Posted: Sun Apr 22, 2007 11:59 am |
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Ten years ago, scientists predicted that the animal z would become extinct in t years. What is t?
(1) Animal z became extinct 4 years ago.
(2) If the scientists had extended their extinction prediction for animal z by 3 years, their prediction would have been incorrect by 2 years.
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StaceyKoprince
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Post subject: ManhattanGMAT Word Translations bank #9 Posted: Tue Apr 24, 2007 1:41 am |
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Posts: 6077
Location: San Francisco
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This one probably seemed a little weird because of the distinction between when the animal actually became extinct and when scientists predicted it. Those are not necessarily the same thing - think of when the meteorologist predicts sunshine tomorrow... and then it rains all day and you don't have an umbrella. In this case, we want to find the prediction.
Statement 1 says nothing about the prediction, just what actually happened.
Statement 2 talks about the prediction, but doesn't tie to any actual numbers.
Statements 1+2 (together) give us some info... but we can ultimately find two different answers. Scientists made the prediction 10 years ago. It actually happened 4 years ago. If the scientists had made a different prediction, they would've been off by 2 years - so if it actually happened 4 years ago, they would've predicted it would happen EITHER 2 or 6 years ago (both are 2 years off of when it really did happen). If 10 years ago they predicted it would happen 2 years prior to now, that would've been 8 years after the prediction. If 10 years ago they predicted it would happen 6 years prior to now, that would've been 4 years after the prediction. Two different answers - so can't answer the question.
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Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT
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daihwa
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Post subject: Posted: Thu Nov 22, 2007 9:33 pm |
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This seemed like a Critical Reasoning question...
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RonPurewal
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Post subject: Posted: Sat Nov 24, 2007 4:50 am |
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arnaud_le_net
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Post subject: Re: Posted: Sun Mar 07, 2010 4:43 am |
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why statement 1 is not sufficient ?
We are in 2010. In 2000, the prediction gave t years for the extinction.
STM1: Extinction occured 4y ago then it occured in 2006. Then t = 2006 - 2000 = 6 ?
What am I doing wrong ????
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tejkumar.m
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Post subject: Re: Online Word Problems #9 Posted: Thu Mar 11, 2010 3:04 am |
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statement 1 is not sufficient because the problem statement just says they have predicted as t years, but it doesnot mention that t is accurate.. i.e. t might be more or less to the actual period. hope this helps
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Ben Ku
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Post subject: Re: Re: Posted: Tue Mar 30, 2010 6:57 pm |
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arnaud_le_net wrote: why statement 1 is not sufficient ?
We are in 2010. In 2000, the prediction gave t years for the extinction.
STM1: Extinction occured 4y ago then it occured in 2006. Then t = 2006 - 2000 = 6 ?
What am I doing wrong ???? arnaud_le_net: You're doing the right math, but you're answering the wrong question. The question is asking when they PREDICT the animal would be extinct; the statement tells us the year the animal ACTUALLY was extinct. We still don't have information about the prediction. Hope that helps.
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Ben Ku
Instructor
ManhattanGMAT
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