Find all School-related info fast with the new School-Specific MBA Forum

It is currently 17 Sep 2014, 01:49

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

For positive integer x, if x^2 has 4 digits, which of the

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 10 Feb 2011
Posts: 116
Followers: 1

Kudos [?]: 26 [0], given: 10

For positive integer x, if x^2 has 4 digits, which of the [#permalink] New post 17 Feb 2011, 14:06
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

78% (02:58) correct 22% (00:56) wrong based on 9 sessions
186. For positive integer x, if x^2 has 4 digits, which of the following must be true?
I. x must be a 2-digit integer
II. 2x must be a 3-digit integer
III. 3x must be a 3-digit integer
(A) I only
(B) II only
(C) III only
(D) I and II only
(E) I and III only
[Reveal] Spoiler: OA
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 29659
Followers: 3494

Kudos [?]: 26255 [0], given: 2708

Re: 186. For positive integer x, if x2 has 4 digits, which of th [#permalink] New post 17 Feb 2011, 15:15
Expert's post
banksy wrote:
186. For positive integer x, if x^2 has 4 digits, which of the following must be true?
I. x must be a 2-digit integer
II. 2x must be a 3-digit integer
III. 3x must be a 3-digit integer
(A) I only
(B) II only
(C) III only
(D) I and II only
(E) I and III only


As x is an integer and x^2 is a 4-digit perfect square then 32\leq{x}\leq{99} (32^2=1024 is the first 4-digit perfect square and 100^2=10,000 is already a 5-digit perfect square).

Hence only I must be true (if x=32 then 2x=64 and 3x=96 so not the 3-digit integers).

Answer: A.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Re: 186. For positive integer x, if x2 has 4 digits, which of th   [#permalink] 17 Feb 2011, 15:15
    Similar topics Author Replies Last post
Similar
Topics:
5 If x and y are positive integers, and 4x^2=3y, then which of goodyear2013 2 03 Aug 2014, 03:24
3 Experts publish their posts in the topic If x is a positive integer, is (x)(x + 2)(x + 4) div by 12? aeros232 2 26 Nov 2012, 08:40
3 Experts publish their posts in the topic If x is a positive integer, what is the units digit of x^2? marcusaurelius 5 17 May 2010, 14:52
x10x is a 4 digit integer divisible by 6. What is x? 2 3 4 5 bmwhype2 5 21 Nov 2007, 08:54
X is a 2-digit positive integer, what is the tens' digit of getzgetzu 3 06 May 2006, 03:27
Display posts from previous: Sort by

For positive integer x, if x^2 has 4 digits, which of the

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.