Need clarification on a simple concept!!

manred

This is a DS question from PR Math Bin 1.

What is the value of x?

(1) x^2 = 4x (^ is my representation of to the power of)
(2) x is an even integer.

The choice are standard DS choices.

My answer was (C) BOTH statements together are sufficient but NEITHER statement alone is sufficient.

My solution is as follows:

x^2 = 4x
x^2 - 4x =0
x(x-4) = 0

So x=0 or x=4. So (1) alone not sufficeint.

(2) alone not sufficent.

Combining (1) and (2) we can get the value of x as 4, since zero (0) is neither even nor odd. So my answer was (C).

But the book says the answer is (E) Statements (1) and (2) TOGETHER are NOT sufficient.

All the calculations in the book were similar and it boils down to x=4 and x=0. But book says both 4 and 0 are even, so combining both is also not sufficient to determine the value of x.

As far as my knowledge goes 0 is neither even not odd. But the book says 0 is even. this was quite surprising for me. Is it GMAT Math?? or a mistake by PR guys.

Need clarification form u guys

manred · Posted: Mon Jul 09, 2007 9:32 pm Post subject: Search doesnt clarify

I have done some search on the web and still the ocnfusion remains. Some resources say that zero is even and the others claim it is neither even nor odd. But the majority says its even.

Yes, zero has been a topic of debate for mathematicians since ages and still is. But right now Iam only concerned about what the mathematicians at GMAC think about Zero. Guys anyone sure what GMAC thinks about Zero?

gabriel · Posted: Mon Jul 09, 2007 11:29 pm Post subject: Re: Search doesnt clarify

discreet · Posted: Tue Jul 10, 2007 5:34 am Post subject:

Maths cannot be different for GMAT Wink

The concepts remain the same everywhere.

Note : Zero is neither positive nor negative.I guess you twisted it to neither even nor odd Smile

Zero is an even number\integer....To confirm what GMAC thinks....

Refer OG 11 - Page number 108

It says ..... "0,2,4,6.... are consecutive even integers"

Guest · Posted: Tue Jul 10, 2007 6:37 am Post subject:

Agreed, zero is an even integer.

It would be worth studying our properties of numbers GMAT tutorial to make sure you are clear on the math concepts you need.

Best of luck,

Joel

manred · Posted: Tue Jul 10, 2007 5:59 pm Post subject:

thanks everybody for the clarification. Just a note that a few resources on the internet claim zero to be neither even nor odd. They have their own valid reasoning which cannot be ignored though.