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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach Starts Oct 17
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Chris Peckover, 100th-Percentile GMAT Scorer

Oct 17 · Chris Peckover
Sat · 11:00 AM to 2:00 PM ET
Oct 20 · Chris Peckover
Tue, Thu · 8:00 to 10:00 PM ET
Oct 25 · Josh Braslow
Sun · 1:00 to 4:00 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemand 5 seats left Start anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Rooted to roots

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Legendary Member
Posts: 2326
Joined: Mon Jul 28, 2008 3:54 amFollowed by: 2 members
Thanked: 173 times
GMAT Score:710

by gmatmachoman » Mon Feb 15, 2010 10:49 pm
IMO C
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pmFollowed by: 2 members
Location: Gandhinagar
Thanked: 41 times

by shashank.ism » Mon Feb 15, 2010 11:28 pm
austin wrote:If f(x) = x^n - a = 0, how many REAL roots does x have?

(1) a < 0
(2) n = 2k, where k is a positive integer
x^n - a = 0 --> x= a^(1/n)
so there can be many solution depending on a and n
St. 1: a<0 i.e. -ve values then also many soln. --------------not sufficient
St. 2: n=2k then also many soln. --------------not sufficient
combined : since a is -ve and and we are taking nth root where n is even (as n=2k)
so there will be no solution
Hence, it is sufficient Ans C
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members
Location: Arabian Sea
Thanked: 125 times

by ajith » Mon Feb 15, 2010 11:59 pm
austin wrote:If f(x) = x^n - a = 0, how many REAL roots does x have?

(1) a < 0
(2) n = 2k, where k is a positive integer
1) a<0
is not sufficient
Say when n = 1 and a= -3
x+3 has one root x = -3
when n =2 and a= -3
x^2+3 = 0 doesn't have real roots

2) n = 2k is not sufficient

say k = 1 and a = 1
it has 2 roots
x^2-1 =0 has 2 roots

say k = 1 and a = -1
x^2+1=0 has 0 roots

Combining

x^2k + (a positive number) =0 doesnt have any real roots
So, C
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

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

by Ian Stewart » Tue Feb 16, 2010 12:55 am
austin wrote:If f(x) = x^n - a = 0, how many REAL roots does x have?

(1) a < 0
(2) n = 2k, where k is a positive integer
There's an issue with the wording here. When the question uses the word 'roots', what it means is 'solutions to the equation'. It makes no sense to talk about how many 'roots' x has in that case; they mean to ask how many roots 'x^n - a = 0' has, or as is sometimes said, how many roots f(x) has. If you simply talk about the 'roots' of a number or letter, it would be natural to take that to mean square roots, cube roots, and so on, which is not at all what the question is talking about. If the wording in the post above is that used in the source, then there are problems with that source.
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
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 110
Joined: Thu Oct 23, 2008 9:12 amFollowed by: 1 member
Location: India
Thanked: 9 times

by austin » Tue Feb 16, 2010 3:12 am
Ian,

You are right, it has to be f(x).
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1022
Joined: Mon Jul 20, 2009 11:49 pmFollowed by: 2 members
Location: Gandhinagar
Thanked: 41 times

by shashank.ism » Sun Feb 21, 2010 9:03 pm
Ian Stewart wrote:
austin wrote:If f(x) = x^n - a = 0, how many REAL roots does x have?

(1) a < 0
(2) n = 2k, where k is a positive integer
There's an issue with the wording here. When the question uses the word 'roots', what it means is 'solutions to the equation'. It makes no sense to talk about how many 'roots' x has in that case; they mean to ask how many roots 'x^n - a = 0' has, or as is sometimes said, how many roots f(x) has. If you simply talk about the 'roots' of a number or letter, it would be natural to take that to mean square roots, cube roots, and so on, which is not at all what the question is talking about. If the wording in the post above is that used in the source, then there are problems with that source.
ian that was a nice explanation related to roots..will keep it in mind.
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 194
Joined: Thu Jan 14, 2010 5:18 am
Thanked: 2 times

by girish3131 » Tue Mar 09, 2010 1:21 am
IMO A

b'cos ques ans how many real roots r thr..

so option A says that NO SOLUTION.... so that mean we get ans A

ta
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1