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algebra

by vscid » Sat Dec 20, 2008 6:23 pm
If x^3y^4 = 5000, what is the value of y?

1] y is positive
2] x is an integer

-------------------------
Please give explanations.
The GMAT is indeed adaptable. Whenever I answer RC, it proficiently 'adapts' itself to mark my 'right' answer 'wrong'.
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Re: algebra

by logitech » Sat Dec 20, 2008 6:37 pm
vscid wrote:If x^3y^4 = 5000, what is the value of y?

1] y is positive
2] x is an integer

-------------------------
Please give explanations.
5000 = 5^4 2^3

x^3y^4 = 5^4 2^3

( I might be missing something here with integers but ) y^4=5^4

since 5^4 = (-5)^4 we need to know the sign of the Y to answer the question.

Statement 1 gives us this information, but statement 2 does not; therefore I choose A
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by cramya » Sat Dec 20, 2008 6:50 pm
Stmt I

5000 = 5^4*2^3

Stmt I

y is posItive (doesnt say integer) but can only be 5 and not -5

SUFF

Stmt II

x is an integer

y could be -5 or 5

INSUFF

Choose A)
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by 720dreaming » Sat Dec 20, 2008 7:15 pm
Used the same method as above, same answer. However, I was not sure about A:

How can we be sure that both X and Y are integers?

If we know that X is an Integer I think its safe to assume that Y is also...and vice versa. But, in A, we don't know that...

For now, I suppose we can just assume that the GMAT is not THAT cruel!
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by iamcste » Sat Dec 20, 2008 7:17 pm
I feel more toward C

How can one assume that X can only be an integer

It could be any value

I may be incorrect But want to know how have you guys ensured that X can only be 2 and not any other value or a a decimal

Or is it an incomplete solution
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by cramya » Sat Dec 20, 2008 7:25 pm
How can one assume that X can only be an integer
Good question; thought about it since no info was given. But 8 can only be 1 number's cube and that is 2. I am not sure if any other number cubed would be 8.

If it is then I may be missing something.
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by logitech » Sat Dec 20, 2008 7:30 pm
cramya wrote:
How can one assume that X can only be an integer
Good question; thought about it since no info was given. But 8 can only be 1 number's cube and that is 2. I am not sure if any other number cubed would be 8.

If it is then I may be missing something.
that was the same FLY in my SOUP! :)
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by vscid » Sat Dec 20, 2008 7:45 pm
Put y = 5 ^1/4. or better yet, x = 10.
The GMAT is indeed adaptable. Whenever I answer RC, it proficiently 'adapts' itself to mark my 'right' answer 'wrong'.
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by iamcste » Sat Dec 20, 2008 7:48 pm
vscid wrote:Put y = 5 ^1/4. or better yet, x = 10.

:P
hence DS is always a fun...
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by iamcste » Sat Dec 20, 2008 7:49 pm
IMO E

qtn doesnt specifiy whether Y is an integer.
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by 720dreaming » Sat Dec 20, 2008 7:53 pm
Yep, If X is 10, it throws off everything. Looks like E.
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by cramya » Sat Dec 20, 2008 7:55 pm
I think we have gone through every choice from A TO E with the exception of B :D

Iamcaste E should be it.



Vsicd,

Pretty good one.
If u could post the official ans that would be great
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by logitech » Sat Dec 20, 2008 8:01 pm
We can not discriminate. B IT IS THAN!! :)
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by vscid » Sat Dec 20, 2008 8:16 pm
logitech wrote:We can not discriminate. B IT IS THAN!! :)
B? how come you got B now? :shock:
The GMAT is indeed adaptable. Whenever I answer RC, it proficiently 'adapts' itself to mark my 'right' answer 'wrong'.
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by vscid » Sat Dec 20, 2008 8:27 pm
By the way, on a scale of 1 to 10, how much would you guys rate this question (with regards to GMAT difficulty level), 10 being most difficult?
The GMAT is indeed adaptable. Whenever I answer RC, it proficiently 'adapts' itself to mark my 'right' answer 'wrong'.
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