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 the integer x a 3-digit integer?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 394
Joined: Sun Jul 02, 2017 10:59 amFollowed by: 5 members
Thanked: 1 times
by AbeNeedsAnswers » Sat Apr 27, 2019 8:47 pm

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

Is the integer x a 3-digit integer?

(1) x is the square of an integer.
(2) 90 < x < 150

C

Source: Official Guide 2020
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |

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 Apr 28, 2019 6:49 am
AbeNeedsAnswers wrote:Is the integer x a 3-digit integer?

(1) x is the square of an integer.
(2) 90 < x < 150
Target question: Is the integer x a 3-digit integer?

Statement 1: x is the square of an integer.
Let's TEST some values.
There are several values of x that satisfy statement 1. Here are two:
Case a: x = 10² = 100. In this case, the answer to the target question is YES, x IS a 3-digit integer
Case b: x = 9² = 81. In this case, the answer to the target question is NO, x is NOT a 3-digit integer
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: 90 < x < 150
TEST some cases.
Case a: x = 100. In this case, the answer to the target question is YES, x IS a 3-digit integer
Case b: x = 91. In this case, the answer to the target question is NO, x is NOT a 3-digit integer
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
There are THREE values of x that satisfy BOTH statements: x = 100, x = 121 and x = 144
In all three cases, the answer to the target question is the same: YES, x IS a 3-digit integer
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

GMAT/MBA Expert

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

by [email protected] » Sun Apr 28, 2019 11:28 am
Hi All,

We're told that X is an integer. We're asked if X is a 3-digit integer. This question can be solved by TESTing VALUES.

(1) X is the SQUARE of an INTEGER.

Fact 1 tells us that X is a 'perfect square.' For example, X could be 1, 4, 9.....100, 121, 144....10,000, etc.
IF....
X = 1, then the answer to the question is NO.
X = 100, then the answer to the question is YES.
Fact 1 is INSUFFICIENT

(2) 90 < X < 150

Fact 2 gives us a range of possible values for X.
IF....
X = 91, then the answer to the question is NO.
X = 100, then the answer to the question is YES.
Fact 2 is INSUFFICIENT

Combined, we know...
X is the SQUARE of an INTEGER.
90 < X < 150

There are only a few perfect squares in this given range: 100, 121 and 144. Regardless of which value X actually is, the answer to the question is ALWAYS YES.
Combined, SUFFICIENT

Final Answer: C

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 62
Joined: Wed Nov 13, 2019 9:42 pm

by SampathKp » Wed Dec 18, 2019 4:32 am
AbeNeedsAnswers wrote:Is the integer x a 3-digit integer?

(1) x is the square of an integer.
(2) 90 < x < 150

C

Source: Official Guide 2020
A square of Integer can be positive single digit (4, 9), two digits (16, 25, 36, 49, 64, 81) , 3 digits, (100, 121, 144, 169, 186.......) and 4 digits ( 1225 etc.... )So we can definetely not say a square of an integer X is 3 digit number. SO (1) is in iteself not sufficient.

In (2) X ranges from 91 to 149 so we cannot conclude that X is 3 digit integer (91 to 99 are 2 digit integers and 100 to 149 are 3 digit integers) . So (2) alone is NOT sufficient.

Combining 1 and 2 we have X as 100, 121 and 144 which are squares of 10, 11 and 12 and are in between 91 and 149. So we can conclude that X is 3 digit integer.

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