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

It is currently 22 Oct 2018, 22:47

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

If a, b & c are integers, is abc odd?

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

Hide Tags

Manager
Manager
User avatar
S
Joined: 25 Sep 2018
Posts: 85
Location: United States (CA)
Concentration: Finance, Strategy
GMAT 1: 640 Q47 V30
GPA: 3.97
WE: Investment Banking (Investment Banking)
If a, b & c are integers, is abc odd?  [#permalink]

Show Tags

New post 27 Sep 2018, 07:50
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

82% (00:36) correct 18% (00:51) wrong based on 68 sessions

HideShow timer Statistics

If a, b & c are integers, is abc odd?

(1) ab is odd
(2) bc is odd

_________________

Why do we fall?...So we can learn to pick ourselves up again



If you like the post, give it a KUDOS!

Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 6980
Re: If a, b & c are integers, is abc odd?  [#permalink]

Show Tags

New post 27 Sep 2018, 19:59
2
Abhi077 wrote:
If a, b & c are integers, is abc odd?

(1) ab is odd
(2) bc is odd


for abc is odd, each of them should be ODD...

(1) ab is odd
nothing about C
insuff

(2) bc is odd
nothing about a
insuff

combined
ab*bc is odd, so all 3 integers are odd
suff
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 12700
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: If a, b & c are integers, is abc odd?  [#permalink]

Show Tags

New post 28 Sep 2018, 19:05
Hi All,

We're told that A, B and C are INTEGERS. We're asked if (A)(B)(C) is ODD. This is a YES/NO question and can be solved with Number Properties and TESTing VALUES.

1) (A)(B) is ODD

Since A and B are both integers, the only way the product of those two numbers to be odd is if BOTH A and B are ODD. However, we don't know whether C is odd or even.
IF...
A=1, B=1, C=1, then (A)(B)(C) = 1 and the answer to the question is YES
A=1, B=1, C=2, then (A)(B)(C) = 2 and the answer to the question is NO
Fact 1 is INSUFFICIENT

2) (B)(C) is ODD

Since B and C are both integers, the only way the product of those two numbers to be odd is if BOTH B and C are ODD. However, we don't know whether A is odd or even.
IF...
A=1, B=1, C=1, then (A)(B)(C) = 1 and the answer to the question is YES
A=2, B=1, C=1, then (A)(B)(C) = 2 and the answer to the question is NO
Fact 2 is INSUFFICIENT

Combined, we know...
A and B are ODD
B and C are ODD
Thus, (A)(B)(C) will ALWYS be ODD and the answer to the question is ALWAYS YES.
Combined, SUFFICIENT

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****

Target Test Prep Representative
User avatar
P
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 3906
Location: United States (CA)
Re: If a, b & c are integers, is abc odd?  [#permalink]

Show Tags

New post 02 Oct 2018, 20:00
Abhi077 wrote:
If a, b & c are integers, is abc odd?

(1) ab is odd
(2) bc is odd


We need to determine whether abc is odd.

Statement One Alone:

ab is odd

Since ab is odd, we know that both a and b are odd. However, without knowing anything about c we cannot answer the question. Statement one alone is not sufficient.

Statement Two Alone:

bc is odd

Since ab is odd, we know that both b and c are odd. However, without knowing anything about a we cannot answer the question. Statement two alone is not sufficient.

Statements One and Two Together:

Using the information from both statements we see that a, b, and c must all be odd, so the product of a, b, and c is odd.

Answer: C
_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

GMAT Club Bot
Re: If a, b & c are integers, is abc odd? &nbs [#permalink] 02 Oct 2018, 20:00
Display posts from previous: Sort by

If a, b & c are integers, is abc odd?

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


Copyright

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®.