It is currently 19 Oct 2017, 05:57

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If a and b are positive integers (a > b), is a^2 - b^2

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Senior Manager
Senior Manager
avatar
Joined: 05 Oct 2008
Posts: 270

Kudos [?]: 538 [0], given: 22

If a and b are positive integers (a > b), is a^2 - b^2 [#permalink]

Show Tags

New post 07 Nov 2008, 07:36
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If a and b are positive integers (a > b), is a^2 - b^2 divisible by 4?

1. a = b + 2
2. a and b are odd

Kudos [?]: 538 [0], given: 22

Manager
Manager
User avatar
Joined: 05 Jul 2008
Posts: 136

Kudos [?]: 123 [0], given: 40

GMAT 2: 740 Q51 V38
Re: No. Properties [#permalink]

Show Tags

New post 07 Nov 2008, 07:47
study wrote:
If a and b are positive integers (a > b), is a^2 - b^2 divisible by 4?

1. a = b + 2
2. a and b are odd


a2-b2= (a-b)(a+b)

1. a = b + 2 => a-b and a+b are even
Enough
2. a and b are odd => a-b and a+b are even
Enough
So D

Kudos [?]: 123 [0], given: 40

VP
VP
User avatar
Joined: 05 Jul 2008
Posts: 1402

Kudos [?]: 437 [0], given: 1

Re: No. Properties [#permalink]

Show Tags

New post 07 Nov 2008, 09:13
study wrote:
If a and b are positive integers (a > b), is a^2 - b^2 divisible by 4?

1. a = b + 2
2. a and b are odd


D

Q is asking whether (a-b) (a+b) is divisible by 4, given a,b >0 and int

a= b+2 means it comes down to 2 (2b+2) which is 4 (b+1) . Yes divisible by 4

a and b are odd. Both sum and difference are even. Two even numbers. That means there must be atleast two 2's . Hence product is divisible by 4

Kudos [?]: 437 [0], given: 1

Manager
Manager
avatar
Joined: 11 Apr 2008
Posts: 202

Kudos [?]: 18 [0], given: 1

Re: No. Properties [#permalink]

Show Tags

New post 07 Nov 2008, 12:43
Yea the ans should be D
_________________

Nobody dies a virgin, life screws us all.

Kudos [?]: 18 [0], given: 1

SVP
SVP
User avatar
Joined: 30 Apr 2008
Posts: 1867

Kudos [?]: 615 [0], given: 32

Location: Oklahoma City
Schools: Hard Knocks
Re: No. Properties [#permalink]

Show Tags

New post 07 Nov 2008, 13:00
Did anyone else use number picking?
_________________

------------------------------------
J Allen Morris
**I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.

GMAT Club Premium Membership - big benefits and savings

Kudos [?]: 615 [0], given: 32

Re: No. Properties   [#permalink] 07 Nov 2008, 13:00
Display posts from previous: Sort by

If a and b are positive integers (a > b), is a^2 - b^2

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.