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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Is it true that x > 0?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Sun Mar 24, 2019 2:51 am
BTGmoderatorDC wrote:Is it true that x > 0?

(1) x^2 = 2x
(2) x^3 = 3x
Statement 1:
Case 1: x=0
In this case, the answer to the question stem is NO.
Case 2: x≠0, allowing us to divide both sides by x
x²/x = 2x/x
x = 2
In this case, the answer to the question stem is YES.
INSUFFICIENT.

Statement 2:
Case 1: x=0
In this case, the answer to the question stem is NO.
Case 2: x≠0, allowing us to divide both sides by x
x³/x = 3x/x
x² = 3
x = ±√3
If x=√3, the answer to the question stem is YES.
INSUFFICIENT.

Statements combined:
Only x=0 satisfies both statements.
Thus, the answer to the question stem is NO.
SUFFICIENT.

The correct answer is C.
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
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Sun Mar 24, 2019 6:29 am
BTGmoderatorDC wrote:Is it true that x > 0?

(1) x² = 2x
(2) x³ = 3x
Target question: Is it true that x > 0?

Statement 1: x² = 2x
Rewrite as: x² - 2x = 0
Factor: x(x - 2) = 0
So, EITHER x = 0 OR x = 2
Let's examine each possible case
Case a: If x = 0, then the answer to the target question is NO, it is not true that x > 0
Case b: If x = 2, then the answer to the target question is YES, it is true that x > 0
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: x³ = 3x
Rewrite as: x³ - 3x = 0
Factor: x(x² - 3) = 0
Factor again: x(x - √3)(x + √3) = 0
So, x = 0, OR x = √3 OR x = -√3
Let's examine each possible case
Case a: If x = 0, then the answer to the target question is NO, it is not true that x > 0
Case b: If x = √3, then the answer to the target question is YES, it is true that x > 0
Case c: If x = -√3,, then the answer to the target question is NO, it is not true that x > 0
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 1 tells us that x = 0 OR x = 2
Statement 2 tells us that x = 0, OR x = √3 OR x = -√3
The only x-value that satisfies BOTH statements is x = 0
So, the answer to the target question is NO, it is not true that x > 0
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer: C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1