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

It is currently 30 Sep 2014, 16:22

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

Number properties Q10

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 07 Oct 2009
Posts: 33
Followers: 0

Kudos [?]: 3 [0], given: 1

Number properties Q10 [#permalink] New post 02 Jan 2010, 05:27
Is the product of four consecutive even integers positive?
1. The sum of these integers is positive but smaller than 20
2. The product of the middle two of these integers is positive

• Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
• Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
• BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
• EACH statement ALONE is sufficient
• Statements (1) and (2) TOGETHER are NOT sufficient

I marked 'B' but OA is 'A'.Can someone help me understand this.Thanks!
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23064
Followers: 3538

Kudos [?]: 27237 [0], given: 2725

Re: Number properties Q10 [#permalink] New post 02 Jan 2010, 08:34
Expert's post
rajkar001 wrote:
Is the product of four consecutive even integers positive?
1. The sum of these integers is positive but smaller than 20
2. The product of the middle two of these integers is positive

I marked 'B' but OA is 'A'.Can someone help me understand this.Thanks!


First of all: the product of four consecutive even integers can be either 0 or positive:
If all terms are positive, product will be positive;
If one of the terms is zero, product will be zero;
If all terms are negative, product will be positive.
Note: no other option is possible for 4 consecutive integers.

(1) The sum of these integers is positive but smaller than 20:

If the greatest term is >=8, eg {2,4,6,8}, then the sum will be equal or more than 20.
If the smallest term <-2, eg {-4,-2,0,2}, then the sum won't be positive.

Hence this statement gives only TWO possible sets {0,2,4,6} and {-2,0,2,4} --> sum<20 and product =0, which is not positive hence sufficient to answer the question. Sufficient.

(2) The product of the middle two of these integers is positive.

It's possible to have {0,2,4,6} --> product zero OR {2,4,6,8} --> product positive OR {-8,-6,-4,-2}--> product positive.

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

Intern
Intern
avatar
Joined: 07 Oct 2009
Posts: 33
Followers: 0

Kudos [?]: 3 [0], given: 1

Re: Number properties Q10 [#permalink] New post 02 Jan 2010, 09:46
Thanks GMAT Quant Forum Moderator!

actually i missed the word 'positive' in stmt1.
Re: Number properties Q10   [#permalink] 02 Jan 2010, 09:46
    Similar topics Author Replies Last post
Similar
Topics:
Q10: A set of numbers has the property that for any number t jet1445 6 04 Jul 2007, 19:56
Number Property govinam 4 19 Sep 2006, 15:04
Number Properties govinam 3 10 Sep 2006, 11:43
Number properties vibha 6 03 Apr 2006, 19:00
Number Properties yb 3 19 Oct 2005, 17:14
Display posts from previous: Sort by

Number properties Q10

  Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: Bunuel, WoundedTiger



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®.