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GMATPrep Paper Test Problem

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by sudhir3127 » Mon Aug 11, 2008 7:44 am
My answer is A.

u just have to know the forumla a^2-b^2 = (a+b)(a-b)..ur done !!!

(2^2-1)(2^2+1) (2^4+1) (2^8+1)

the first two terms are in the form of (a+b)(a-b)

hence can be written as 2^4-1

thus the equation now is

(2^4-1) (2^4+1) (2^8+1)

again the first two terms are in that form
hence can written as 2^8-1

now the equation is
(2^8-1) (2^8+1)

thus its 2^16-1.


please let me know if u still have doubts..
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by pepeprepa » Mon Aug 11, 2008 7:49 am
Yep I agree
(a+b)(a-b)=a^2 - b^2 is important, as soon as you see figures which can use this formula, it will help you a lot.
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by NDLadyzman » Mon Aug 11, 2008 8:16 am
Thank you all very much!! Now it looks easy.
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Junior | Next Rank: 30 Posts
Posts: 21
Joined: Mon Feb 26, 2007 11:42 am

by NDLadyzman » Mon Aug 11, 2008 8:18 am
Thank you all very much!! Now it looks easy.
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