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

Redeem

Inequality

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
User avatar
GMAT Instructor
Posts: 1248
Joined: Thu Mar 29, 2012 2:57 pm
Location: Everywhere
Thanked: 503 times
Followed by:192 members
GMAT Score:780

by Bill@VeritasPrep » Fri Feb 07, 2014 1:35 am
1. Take the square root of both sides: x - 1 > 2 or x - 1 < -2. Since x must be positive, we can disregard the second one. If x - 1 > 2, then x > 3. Sufficient

2. Again, take the square root of both sides (and we can again disregard the negative root): x - 2 > 3, so x > 5. Sufficient.
Join Veritas Prep's 2010 Instructor of the Year, Matt Douglas for GMATT Mondays

Visit the Veritas Prep Blog

Try the FREE Veritas Prep Practice Test
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Fri Feb 07, 2014 1:47 am
abhirup1711 wrote:If x is positive, is x > 3 ?
(1) (x - 1)^2 > 4
(2) (x - 2)^2 > 9
Test the THRESHOLD.
Here, the threshold is x=3.

Statement 1: (x-1)² > 4
If x=3, then (x-1)² = 4.
Implication:
To satisfy the constraint that (x-1)² > 4, x>3.
SUFFICIENT.

Statement 2: (x-2)² > 9
If x=3, then (x-2)² = 1.
Implication:
To satisfy the constraint that (x-2)² > 9, x>3.
SUFFICIENT.

The correct answer is D.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Fri Feb 07, 2014 3:23 pm
Hi abhirup1711,

When facing these types of situations, sometimes its best to just "step back" and ask "what fits?"

We're told that X is POSITIVE, which is a great "restriction" (it means that we don't have to think about 0 or negatives). We're asked "is X > 3?" This is a YES/NO question.

Fact 1: (X-1)^2 > 4

With the squared term, I'd normally be thinking about positives AND negatives; remember though that negatives are NOT an option on this question.

Think of it in this way:

(Number)^2 > 4

The Number in the parentheses has to be greater than 2.

X - 1 > 2
X > 3
The answer to the question is ALWAYS YES.
Fact 1 is SUFFICIENT.

Fact 2: (X-2)^2 > 9

Here we have:

(Number)^2 > 9

The Number in parentheses has to be greater than 3

X - 2 > 3
X > 5
The answer to the question is ALWAYS YES.
Fact 2 is SUFFICIENT.

Final Answer: D

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Sat Feb 08, 2014 1:40 am
abhirup1711 wrote:If x is positive, is x > 3 ?
(1) (x - 1)^2 > 4
(2) (x - 2)^2 > 9
(1) If x > 0 and (x - 1)^2 > 4, then 1, 2, 3 doesn't fit into it, any number greater than 3 would make it true, hence YES, x > 3. Sufficient

(2) If x > 0 and (x - 2)^2 > 9, then 1, 2, 3, 4, or 5 doesn't fit into it, any number greater than 5 would make it true, hence [spoiler]YES, x > 3. Sufficient

Pick D[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Post new topic Post Reply
• Page 1 of 1