wait what?
something is seriously wrong here, as elementary number picking is quick to show.
first off, the 2's clearly cancel, so get rid of them.
if we let x = 2 and y = 1/2, then the expression is (5/2)^2 / (3/2)^2, which is 25/9 = 2.77777..., an answer that is clearly not listed. worse yet, plugging in other numbers leads to other answer choices.
incidentally, the only numbers that satisfy the initial constraint (xy = 1) and actually give the answer 16 are plus or minus (√15)/5 and (√15)/3 - two numbers that, i can confidently say, no one is going to pick anytime soon.
GMAT Prep algebra
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lunarpower
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Ron has been teaching various standardized tests for 20 years.
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lunarpower
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wait, uh, well, i made up a problem that looks at least somewhat like this one, with the desired solution.
here you go:
here you go:
Ron has been teaching various standardized tests for 20 years.
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simplyjat
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This question is a mistake in GMATPrep, The original intent of the question is to ask
If XY = 1
Than what is the value of (2^[(x+y)^2])/(2^[(x-y)^2]) ?
Which simplifies to
(2^(x^2))*(2^(y^2))*(2^(2xy)) / (2^(x^2))*(2^(y^2))*(2^(-2xy))
=> (2^(2xy)) / (2^(-2xy))
=> (2^(4xy))
=> (2^(4*1))
=> 2^4
=> 16
If XY = 1
Than what is the value of (2^[(x+y)^2])/(2^[(x-y)^2]) ?
Which simplifies to
(2^(x^2))*(2^(y^2))*(2^(2xy)) / (2^(x^2))*(2^(y^2))*(2^(-2xy))
=> (2^(2xy)) / (2^(-2xy))
=> (2^(4xy))
=> (2^(4*1))
=> 2^4
=> 16
simplyjat
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lunarpower
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that's awesomesimplyjat wrote:This question is a mistake in GMATPrep, The original intent of the question is to ask
If XY = 1
Than what is the value of (2^[(x+y)^2])/(2^[(x-y)^2]) ?
Which simplifies to
(2^(x^2))*(2^(y^2))*(2^(2xy)) / (2^(x^2))*(2^(y^2))*(2^(-2xy))
=> (2^(2xy)) / (2^(-2xy))
=> (2^(4xy))
=> (2^(4*1))
=> 2^4
=> 16
where'd you get the fix? did you figure it out yourself?
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
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simplyjat
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Actually the correct question is stated in OG. I can't remember the exact question number, but I remember solving the question from one of the books...
simplyjat
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simplyjat
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Yesterday, I was giving the GMAT prep and the same question popped up for me. But amazingly the formatting was correct! It seems that there can be a problem with your GMATPrep setup.
vinviper1 can you let us know the setup: Operating System and Java Run-time version. To see the version of windows right-click "My computer" and select "Properties". To see the version of Java run time environment, on command prompt type "java -version".
It would be really helpful for other people...
vinviper1 can you let us know the setup: Operating System and Java Run-time version. To see the version of windows right-click "My computer" and select "Properties". To see the version of Java run time environment, on command prompt type "java -version".
It would be really helpful for other people...
simplyjat
