BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Need help with a question

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon Jan 17, 2011 7:25 am
Thanked: 1 times

Need help with a question

by nikunjd05 » Mon Mar 28, 2011 8:58 am
If x is an odd negative integer and y is an even integer, which of the following statements must be true?

I. (3x - 2y) is odd

II. xy2 is an even negative integer *(It is x times y squared)

III. (y2 - x) is an odd negative integer *(It is y squared)

My answer is II only

I will let you know the answer after someone replies with their answer and explanation.

* Sorry, I don't know how to superscript
Top
Source: — Quantitative Reasoning |
User avatar
Senior | Next Rank: 100 Posts
Posts: 77
Joined: Fri Mar 11, 2011 8:55 am
Thanked: 12 times

by wayofjungle » Mon Mar 28, 2011 3:45 pm
I think the answer is I and II.

I. (3x - 2y) is odd

Yes. [(-odd x odd) - (even x even)] = odd - even = odd

II. xy^2 is an even negative integer

Yes. -odd x even x even = -even

III. (y^2 - x) is an odd negative integer

No. even x even - -odd = even
Top
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon Jan 17, 2011 7:25 am
Thanked: 1 times

by nikunjd05 » Tue Mar 29, 2011 5:53 am
Actually the answer is I only

I) 3x-2y = (odd)(odd) - (even)(even) = odd. SUFFICIENT

II) xy^2 = (-3)(0) = 0 (not negative).

III) (y^2-x) = (2^2) - (-3) = +7 (not negative).

The above is their explanation.
Top
User avatar
Senior | Next Rank: 100 Posts
Posts: 77
Joined: Fri Mar 11, 2011 8:55 am
Thanked: 12 times

by wayofjungle » Tue Mar 29, 2011 1:05 pm
Ah the "0 and 1" number cases. This is something I need to remember in data sufficiency.
Top
Junior | Next Rank: 30 Posts
Posts: 20
Joined: Fri Apr 15, 2011 9:02 pm
Thanked: 1 times
Followed by:1 members

by joinashish » Fri Apr 22, 2011 11:35 pm
yep...ans is definitely I only; but let me know whether we can put '0' as an even integer, as y should be an even integer.

thanks
Top
Post new topic Post Reply
• Page 1 of 1