If 4^(4x)= 1600, what is the value of 4^(2x-2)?
a. 40
b. 20
c. 10
d. 5/2
e. 5/4
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700+ quistion
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4GMAT_Mumbai
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Hi Ankrmit,
4^(2x-2) = 4^2x / 4^2
If 4^4x = 1600; 4^2x = 40.
Hence, 4^2x / 4^2 = 40 / 16. Guess it is [spoiler]5/2[/spoiler] Pls highlight if this is right / wrong.
I doubt if this question would be 700+ though ...
4^(2x-2) = 4^2x / 4^2
If 4^4x = 1600; 4^2x = 40.
Hence, 4^2x / 4^2 = 40 / 16. Guess it is [spoiler]5/2[/spoiler] Pls highlight if this is right / wrong.
I doubt if this question would be 700+ though ...
Last edited by 4GMAT_Mumbai on Fri Jul 09, 2010 12:02 am, edited 1 time in total.
Naveenan Ramachandran
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ankurmit
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Thanks Naveen..its nice explanation but you made some mistake here..check once .. ans is D
Actually I got this quistion in Manhattan test and they marked it as 700+ quistion
and I could not solve it so for me it was definitely a 700+ quistion..
Actually I got this quistion in Manhattan test and they marked it as 700+ quistion
and I could not solve it so for me it was definitely a 700+ quistion..
Last edited by ankurmit on Thu Jul 08, 2010 11:44 pm, edited 1 time in total.
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Rahul@gurome
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4^(4x)= 1600 implies {4^(2x)}^2= 1600 or 4^(2x) = 40
4^(2x-2) = (4^2x)(4^-2) = 40/16 = 5/2
[spoiler]The correct answer is (D).[/spoiler]
4^(2x-2) = (4^2x)(4^-2) = 40/16 = 5/2
[spoiler]The correct answer is (D).[/spoiler]
Rahul Lakhani
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Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
