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

It is currently 03 May 2016, 14:20
GMAT Club Tests

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

If a and b are integers, is b even?

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
1 KUDOS received
Manager
Manager
User avatar
Joined: 26 Jun 2007
Posts: 104
Followers: 2

Kudos [?]: 41 [1] , given: 0

If a and b are integers, is b even? [#permalink]

Show Tags

New post 24 Jan 2008, 03:46
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (04:50) correct 0% (00:00) wrong based on 0 sessions

HideShow timer Statictics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

It has taken me 4+ min to solve. I'm sure there is a method to solve those even\odd DS's.
can't imagine sitting on those Q's more than 2.5 min each in the real GMAT. would any of you people like to share a method for those kind of Q's :?:

If a and b are integers, is b even?

(1) 3a + 4b is even
(2) 3a + 5b is even

I'm less interested in the final answer, more in the way so please explain.

asalways, OA will follow.
Expert Post
1 KUDOS received
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3580
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 474

Kudos [?]: 2708 [1] , given: 359

GMAT ToolKit User Premium Member
Re: DS:SET 21 #11 [#permalink]

Show Tags

New post 24 Jan 2008, 03:58
1
This post received
KUDOS
Expert's post
C

30 sec. all in mind.

1. 3a + 4b is even
1.1. even+even=even ==> a - even, b - even or odd
1.2. odd+odd=even ==> does not work because 4b is always even
insuff.

2. 3a + 5b is even
2.1. even+even=even ==> a - even, b - even
2.2. odd+odd=even ==> a - odd, b - odd
insuff.

1&2. a is even. Therefore, b can be only even.
suff.
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

SVP
SVP
avatar
Joined: 04 May 2006
Posts: 1926
Schools: CBS, Kellogg
Followers: 21

Kudos [?]: 710 [0], given: 1

Premium Member
Re: DS:SET 21 #11 [#permalink]

Show Tags

New post 24 Jan 2008, 03:55
GGUY wrote:
It has taken me 4+ min to solve. I'm sure there is a method to solve those even\odd DS's.
can't imagine sitting on those Q's more than 2.5 min each in the real GMAT. would any of you people like to share a method for those kind of Q's :?:

If a and b are integers, is b even?

(1) 3a + 4b is even
(2) 3a + 5b is even

I'm less interested in the final answer, more in the way so please explain.

asalways, OA will follow.


1.4b is even, no matter what b is!, and 3a+4b is even, so a must be even. No fixed about b, -> not sufficient

2. 3a + 5b even
2.1 even +even =even
2.2 odd +odd = even
so b can be even or odd --> not sufficient

1 and 2 combined is sufficient
from 1, we know a is even, so 3a must be even, and 3a +5b is even, therefore, b must be even --> sufficient

C
_________________

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
User avatar
Joined: 26 Jun 2007
Posts: 104
Followers: 2

Kudos [?]: 41 [0], given: 0

Re: DS:SET 21 #11 [#permalink]

Show Tags

New post 25 Jan 2008, 12:12
walker wrote:
C
30 sec. all in mind.
i wish i had that (in my mind) :wink:
thanks all OA is C

walker +1 (thats the 3rd or 4th kodus I have given you, go buy yourself something nice)
Expert Post
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3580
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 474

Kudos [?]: 2708 [0], given: 359

GMAT ToolKit User Premium Member
Re: DS:SET 21 #11 [#permalink]

Show Tags

New post 25 Jan 2008, 12:51
Expert's post
:) thanks for the question +1
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Re: DS:SET 21 #11   [#permalink] 25 Jan 2008, 12:51
Display posts from previous: Sort by

If a and b are integers, is b even?

  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 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®.