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

It is currently 15 Sep 2014, 21:19

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? (1) 3a + 4b is even. (2)

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 10 Dec 2005
Posts: 103
Followers: 1

Kudos [?]: 8 [0], given: 0

If a and b are integers, is b even? (1) 3a + 4b is even. (2) [#permalink] New post 24 Dec 2005, 21:43
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

50% (00:00) correct 50% (00:06) wrong based on 1 sessions
If a and b are integers, is b even?
(1) 3a + 4b is even.
(2) 3a + 5b is even.

I got the answer, but it took some time working out! Wanted to check any shorter methods!
_________________

JAI HIND!

VP
VP
avatar
Joined: 06 Jun 2004
Posts: 1062
Location: CA
Followers: 2

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

GMAT Tests User
Re: DS: Even integer [#permalink] New post 24 Dec 2005, 22:51
JAI HIND wrote:
If a and b are integers, is b even?
(1) 3a + 4b is even.
(2) 3a + 5b is even.

I got the answer, but it took some time working out! Wanted to check any shorter methods!


My answer is C

For a sum of two numbers to be even..two numbers can either

EVEN + EVEN
ODD + ODD

(1) 3a + 4b is even ==> 4b cannot be odd so it must be the even + even combination. B could be odd or even ==> Insufficient

(2) 3a + 5b is even ==> Could be EVEn + EVEN, ODD + ODD combo. Insufficient

(1) + (2) ==> From (1), we know that 3a must be even...so in (2) 5b must be even as well ==> b = even
_________________

Don't be afraid to take a flying leap of faith.. If you risk nothing, than you gain nothing...

CEO
CEO
User avatar
Joined: 20 Nov 2005
Posts: 2922
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008
Followers: 15

Kudos [?]: 80 [0], given: 0

GMAT Tests User
Re: DS: Even integer [#permalink] New post 25 Dec 2005, 00:14
TeHCM wrote:
JAI HIND wrote:
If a and b are integers, is b even?
(1) 3a + 4b is even.
(2) 3a + 5b is even.

I got the answer, but it took some time working out! Wanted to check any shorter methods!


My answer is C

For a sum of two numbers to be even..two numbers can either

EVEN + EVEN
ODD + ODD

(1) 3a + 4b is even ==> 4b cannot be odd so it must be the even + even combination. B could be odd or even ==> Insufficient

(2) 3a + 5b is even ==> Could be EVEn + EVEN, ODD + ODD combo. Insufficient

(1) + (2) ==> From (1), we know that 3a must be even...so in (2) 5b must be even as well ==> b = even


I got C. I did the same way as done by TeHCM
_________________

SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008

Senior Manager
Senior Manager
User avatar
Joined: 14 Apr 2005
Posts: 422
Location: India, Chennai
Followers: 1

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

GMAT Tests User
Re: DS: Even integer [#permalink] New post 25 Dec 2005, 22:50
JAI HIND wrote:
If a and b are integers, is b even?
(1) 3a + 4b is even.
(2) 3a + 5b is even.

I got the answer, but it took some time working out! Wanted to check any shorter methods!


From 1 we get 3a+4b = 0 mod 2
From 2 we get 3a+5b = 0 mod 2

Subtracting 2 from 1 we get b = 0 mod 2 hence C.
Re: DS: Even integer   [#permalink] 25 Dec 2005, 22:50
    Similar topics Author Replies Last post
Similar
Topics:
If a and b are integers, is b even? (1) 3a + 4b is even. (2) mymba99 4 20 Apr 2008, 06:16
1 If a and b are integers, is b even? (1) 3a + 4b is even (2) neelesh 4 09 Feb 2008, 12:48
If a and b are integers, is b even? (1) 3a + 4b is even (2) GMAT TIGER 3 31 Oct 2007, 20:26
If a and b are integers, is b even? (1) 3a + 4b is even. (2) Tanmoi 6 28 Nov 2005, 07:27
a and b are integers, is b even? (1) 3a+4b is even. (2) pb_india 5 06 Jan 2005, 11:04
Display posts from previous: Sort by

If a and b are integers, is b even? (1) 3a + 4b is even. (2)

  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®.