sequence question

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sequence question

by crak.gmat » Sat Sep 20, 2008 2:09 pm
I found this question a bit tricky. Help pls??



OA B
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by Fab » Sat Sep 20, 2008 2:28 pm
Are you sure OA is B?? I got a C...

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by crak.gmat » Sat Sep 20, 2008 4:53 pm
Yep, I picked C too, but the OA is B. This is a GMATPrep question and they typically don't make mistakes, but this might be one of those rare instances where the OA is wrong.

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by Ian Stewart » Sat Sep 20, 2008 5:11 pm
The OA is correct. The sequence is either constantly increasing or constantly decreasing (since k is nonzero). Using Statement 2, if a_8 is equal to 10, then either every term before a_8 is greater than 10, or every term after a_8 is greater than 10. Either way, seven terms are greater than 10. B.
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by crak.gmat » Sat Sep 20, 2008 5:18 pm
Makes sense. Thanks for the explanation Ian!!