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Fab_Vr6
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 Posted: Tue Jun 12, 2007 11:45 am Post subject: PS question from GMAT PREP test |
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If n and y are positive integers, and 450y= n^3, which of the following must be an integer?
I) y/(3x2^2 x5)
II)y/(3^2 x2x5)
III) y/(3x2x5^2)
A) none
B)I only
C)II only
D)III only
E) I II III |
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Prasanna
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| Posted: Tue Jun 12, 2007 5:03 pm Post subject: Re: PS question from GMAT PREP test |
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| Fab_Vr6 wrote: | If n and y are positive integers, and 450y= n^3, which of the following must be an integer?
I) y/(3x2^2 x5)
II)y/(3^2 x2x5)
III) y/(3x2x5^2)
A) none
B)I only
C)II only
D)III only
E) I II III |
Here 450n should be a cube of an integer. 450 can be factorized as 5*5*3*3*2. For 450y to be a cube y could be equal to 5*3*2*2. From this we know y/(3*2*2*5) will be an integer definitely. Hence option B.
Whats the OA? |
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jayhawk2001
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| Posted: Tue Jun 12, 2007 8:54 pm Post subject: |
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| Another vote for B. |
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