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

Redeem

OG 11 - Algebra Inequalities

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Master | Next Rank: 500 Posts
Posts: 443
Joined: Sat Jun 28, 2008 6:33 pm
Thanked: 5 times

by Vignesh.4384 » Mon Jul 07, 2008 5:07 am
is the answer E ?
Top
Senior | Next Rank: 100 Posts
Posts: 83
Joined: Wed Jun 04, 2008 3:30 am
Thanked: 4 times

by albertrahul » Mon Jul 07, 2008 5:33 am
Dear Vignesh, would you detail your solution please?
OA is not E.
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2623
Joined: Mon Jun 02, 2008 3:17 am
Location: Montreal
Thanked: 1090 times
Followed by:355 members
GMAT Score:780

Re: OG 11 - Algebra Inequalities

by Ian Stewart » Mon Jul 07, 2008 5:48 am
albertrahul wrote:Is m != n?
[!= : not equals]

(1) m + n < 0
(2) mn < 0
Statement 2) is definitely enough on its own: if mn < 0, then m and n have opposite signs, so they can't be equal.

From Statement 1), if m and n are equal and both negative, this will always be true (try m = n = -1). So this is not sufficient; m might be equal to n, and might not.

B.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com
Top
Senior | Next Rank: 100 Posts
Posts: 83
Joined: Wed Jun 04, 2008 3:30 am
Thanked: 4 times

by albertrahul » Mon Jul 07, 2008 5:52 am
Thanks for reply Ian. OG also provides similar solution.

However, I want to know that why can't I assume m = 1/2 and n = 1/2, this also satisfies statement 2.

1/2 * 1/2 = 1/4 < 0
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2623
Joined: Mon Jun 02, 2008 3:17 am
Location: Montreal
Thanked: 1090 times
Followed by:355 members
GMAT Score:780

by Ian Stewart » Mon Jul 07, 2008 7:12 am
albertrahul wrote:Thanks for reply Ian. OG also provides similar solution.

However, I want to know that why can't I assume m = 1/2 and n = 1/2, this also satisfies statement 2.

1/2 * 1/2 = 1/4 < 0
1/4 is not less than zero!
Top
Senior | Next Rank: 100 Posts
Posts: 83
Joined: Wed Jun 04, 2008 3:30 am
Thanked: 4 times

by albertrahul » Mon Jul 07, 2008 9:51 pm
Thanks Ian.
Again, I missed out on basic.
Top
Post new topic Post Reply
• Page 1 of 1