Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
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.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 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
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
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
GMATOnDemandStart 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 563 reviewsTarget Test Prep

DS - Question

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Tue Feb 26, 2013 8:12 am
by neeg » Sun Mar 03, 2013 7:14 am
If d is a positive integer, is sq.rt. d an integer?

(1)Sq.rt.9d is an integer
(2)Sq.rt.10d is an integer
Top
Join the discussion
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pmFollowed by: 523 members
Location: Milpitas, CA
Thanked: 1854 times
GMAT Score:770

by Anurag@Gurome » Sun Mar 03, 2013 7:49 am
neeg wrote:If d is a positive integer, is sq.rt. d an integer?

(1)Sq.rt.9d is an integer
(2)Sq.rt.10d is an integer
[Note : I suspect the actual question says ".. is not an integer." because if √(10d) is an integer, then it is not possible for √d to be an integer which is contradictory to statement 1. I am replying assuming the correction. Otherwise, if the question is considered as posted, both statements will be sufficient to answer the question.]

Statement 1: √(9d) = (√9)*(√d) = 3√d is an integer ---> √d must be an integer

Sufficient

Statement 2: √(10d) = (√10)*(√d) is not an integer
Now, √d may or may not be an integer. For example, consider the following two cases,
  • d = 1 ---> √(10d) is not an integer but √d is an integer
    d = 2 ---> √(10d) as well as √d is not an integer
Not sufficient

The correct answer is A.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
Join the discussion
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Tue Feb 26, 2013 8:12 am

by neeg » Tue Mar 05, 2013 3:43 pm
Yes, it was an error in typing the statements. Statement (2) should have read as sq rt 10d is NOT an integer. Thanks for the solution as I understand the solution now.
Top
Join the discussion