We invite you to test your GMAT knowledge for a chance to win! Each week, we will post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for a free Manhattan GMAT Prep item. Tell your friends to get out their scrap paper and start solving!

Here is this week’s problem:

For positive integers

n, the integer part of thenth term of sequenceAequalsn, while the infinite decimal part of thenth term is constructed in order out of the consecutive positive multiples ofn, beginning with 2n. For instance,A_{1}= 1.2345678…, whileA_{2}= 2.4681012… The sum of the first seven terms of sequenceAis between

To see the answer choices, and to submit your answer, visit our Challenge Problem Showdown page on our site.

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The weekly winner, drawn from among all the correct submissions, will receive One Year of Access to our Challenge Problem Archive, AND the GMAT Navigator, AND Our Six Computer Adaptive Tests ($92 value).