GMAT Prep Number Properties

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GMAT Prep Number Properties

by doclkk » Tue Jul 07, 2009 9:50 pm
If N and Y are positive integers and 450Y = N^3, which of the following must be an integer?

I. Y/(3X2^2X5)
II. Y/(3^2X2X5)
III. Y/(3X2X5^2)

None
I only
II only
III only
I, II, III

OA: [spoiler]B[/spoiler

My thought - [spoiler]I thought since y could = 60 then 60/60 = 1. A[/spoiler]

I didn't really know how to set up besides that.
Source: — Data Sufficiency |

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by aj5105 » Tue Jul 07, 2009 10:09 pm
450 = 5^2 * 3^2 * 2

(5^2 * 3^2 * 2 ) Y = N^3

Therefore, Y = 5 * 3 * 2^2

I guess, the answer is I only.

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by ketkoag » Sat Jul 11, 2009 1:09 am
yeah answer should be B i.e. 1 only.