GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 19 Aug 2018, 18:39

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

Is ab odd? (1) a is even (2) a is an integer

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Senior SC Moderator
User avatar
V
Joined: 14 Nov 2016
Posts: 1322
Location: Malaysia
GMAT ToolKit User Premium Member CAT Tests
Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 21 Mar 2017, 18:21
1
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

41% (00:30) correct 59% (00:23) wrong based on 152 sessions

HideShow timer Statistics

Is ab odd?

(1) a is even
(2) a is an integer

_________________

"Be challenged at EVERY MOMENT."

“Strength doesn’t come from what you can do. It comes from overcoming the things you once thought you couldn’t.”

"Each stage of the journey is crucial to attaining new heights of knowledge."

Rules for posting in verbal forum | Please DO NOT post short answer in your post!

Advanced Search : https://gmatclub.com/forum/advanced-search/

BSchool Forum Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3044
Location: India
GPA: 3.12
Premium Member CAT Tests
Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 21 Mar 2017, 19:33
1. If a is even and b can be fraction which is 1/a and the value of ab is odd.
But if a is even and b is also an integer, then the product of ab is even. Not sufficient.

2. 'a' being an integer is not sufficient to tell us anything about ab,
since we have no information about b. Here ab could be either even or odd. Not sufficient

On combining the information present in both the statements,
we know a is an integer and even, but we have no information about b.
Hence, the value of ab can either be odd or even as already explained in statement 1's explanation (Option E)
_________________

You've got what it takes, but it will take everything you've got

Intern
Intern
avatar
B
Joined: 12 Dec 2010
Posts: 38
GMAT ToolKit User
Re: Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 21 Mar 2017, 23:33
IMHO E

No info is given whether B is an integer


Sent from my ONEPLUS A3003 using GMAT Club Forum mobile app
Senior Manager
Senior Manager
User avatar
B
Status: Come! Fall in Love with Learning!
Joined: 05 Jan 2017
Posts: 434
Location: India
Premium Member
Re: Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 22 Mar 2017, 02:05
ziyuen wrote:
Is ab odd?

(1) a is even
(2) a is an integer



ST 1: a is even. no idea about b as it could be a fraction, decimal etc. INSUFFICIENT
ST 2: a is integer. no idea about b as it could be a fraction, decimal etc. INSUFFICIENT

St1 & St 2: a is even integer, no idea about b as it could be a fraction, decimal etc. INSUFFICIENT
_________________

GMAT Mentors
Image

Intern
Intern
avatar
B
Status: Studying for GMAT
Joined: 06 Jan 2015
Posts: 6
Location: United Kingdom
Re: Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 26 Sep 2017, 02:33
In the Veritas prep book, there is this thinking process called "Why are you here?". I am guessing this applies here (idk, maybe someone from Veritas can confirm this?). I answered this question and got it wrong. I.e. I answered A because here is my thinking process:

Statement 1: a is even. Quoting pushpitkc, If a is even, b being odd/even wouldn't make any difference, because the product will always be even. Hence statement 1 is sufficient because it gives us a definite NO. And hence sufficient.

Statement 2: a is an integer. My thinking is, this has nothing to do with ab being odd or even. Hence, not sufficient.

So in theory, according to OA, I am wrong because I did not think about the "Why are you here?" element. But I somehow cannot brain the "Why are you here?" element in this question.
BSchool Forum Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3044
Location: India
GPA: 3.12
Premium Member CAT Tests
Re: Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 26 Sep 2017, 03:32
1
sarahfiqbal wrote:
In the Veritas prep book, there is this thinking process called "Why are you here?". I am guessing this applies here (idk, maybe someone from Veritas can confirm this?). I answered this question and got it wrong. I.e. I answered A because here is my thinking process:

Statement 1: a is even. Quoting pushpitkc, If a is even, b being odd/even wouldn't make any difference, because the product will always be even. Hence statement 1 is sufficient because it gives us a definite NO. And hence sufficient.

Statement 2: a is an integer. My thinking is, this has nothing to do with ab being odd or even. Hence, not sufficient.

So in theory, according to OA, I am wrong because I did not think about the "Why are you here?" element. But I somehow cannot brain the "Why are you here?" element in this question.



Hi sarahfiqbal,

I had not considered the possibility of b being a fraction.
Eg1 Let a=2, b=\(\frac{1}{2}\). The product of ab is 1 which is odd.
Eg2 Let a=2, b=1. Product of ab is 2, which is even.

Hence the information present in both the statements is not enough to answer that question
So, the answer must be Option E, not A as I had previously marked. Made the necessary changes.

Also, hope that helps you!
_________________

You've got what it takes, but it will take everything you've got

Intern
Intern
avatar
B
Status: Studying for GMAT
Joined: 06 Jan 2015
Posts: 6
Location: United Kingdom
Re: Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 26 Sep 2017, 03:41
pushpitkc Yes, I did the same thing- I didn't consider it to be a fraction. And my thought now is that Statement 2 gives that clue that we are suppose to think about fractions. Which is why I highlighted the Veritas prep books. It has that element of "Why are you here?". So I should practice this way of thinking more.

But thank you for the clarification. Good luck.
Director
Director
User avatar
S
Joined: 08 Jun 2015
Posts: 529
Location: India
GMAT 1: 640 Q48 V29
GMAT 2: 700 Q48 V38
Premium Member CAT Tests
Re: Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 17 Apr 2018, 07:23
+1 for option E.

St 1 - No info on whether a is an integer or any info on b.
St 2 - NS ; No input on whether or not a is an integer.

Both - NS. We still don't know if ab will be an integer or not. The entire product must be divisible by 2. Hence E
_________________

" The few , the fearless "

CEO
CEO
User avatar
D
Joined: 12 Sep 2015
Posts: 2707
Location: Canada
Re: Is ab odd? (1) a is even (2) a is an integer  [#permalink]

Show Tags

New post 08 May 2018, 08:23
Top Contributor
hazelnut wrote:
Is ab odd?

(1) a is even
(2) a is an integer


Target question: Is ab odd?
Since there's no information stating that b is an integer, we can jump straight to.....

Statements 1 and 2 combined
There are several values of a and b that satisfy BOTH statements. Here are two:
Case a: a = 2 and b = 1, in which case ab = (2)(1) = 2. So, ab is NOT odd
Case b: a = 2 and b = 1.5, in which case ab = (2)(1.5) = 3. So, ab IS odd
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,
Brent
_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Re: Is ab odd? (1) a is even (2) a is an integer &nbs [#permalink] 08 May 2018, 08:23
Display posts from previous: Sort by

Is ab odd? (1) a is even (2) a is an integer

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.