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

It is currently 16 Oct 2018, 03:29

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

An even and an odd integer are multiplied together. Which of the follo

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49892
An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 17 Apr 2015, 04:48
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

92% (00:57) correct 8% (00:57) wrong based on 117 sessions

HideShow timer Statistics

An even and an odd integer are multiplied together. Which of the following could not be the square of their product?

(A) 36
(B) 100
(C) 144
(D) 225
(E) 400


Kudos for a correct solution.

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Retired Moderator
avatar
B
Status: On a mountain of skulls, in the castle of pain, I sit on a throne of blood.
Joined: 30 Jul 2013
Posts: 335
GMAT ToolKit User Reviews Badge
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 17 Apr 2015, 05:03
Bunuel wrote:
An even and an odd integer are multiplied together. Which of the following could not be the square of their product?

(A) 36
(B) 100
(C) 144
(D) 225
(E) 400


Kudos for a correct solution.


36=\(6^2\)=2*3--->Possible
100=\(10^2\)=2*5--->Possible
144=\(12^2\)=4*3--->Possible
225=\(15^2\)=3*5--->Not Possible
400=\(20^2\)=4*5--->Possible

Answer: D
EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 12655
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 18 Apr 2015, 11:19
1
Hi All,

This is an example of a question that can be solved with Number Properties; NPs show up in a variety of questions on Test Day (including many DS questions), so putting some extra practice into this category is a good idea for most Test Takers.

Here, we're told to take the product of an EVEN integer and an ODD integer. (Even)(Odd) = Even. Next, we're asked to SQUARE that result. (Even)^2 = Even. The question asks for the answer that could NOT be the result of using these Number Properties as described. Since we know the end result MUST be Even, there's only one answer here that could NOT occur....

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!*****

Intern
Intern
avatar
Joined: 11 Sep 2013
Posts: 21
GMAT 1: 620 Q49 V27
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 18 Apr 2015, 14:32
2
Product of an even and odd integer will at least be divisible by 2

So , if we square the product, then it will be at least divisible by 4

only 225, among the given list of nos is not divisible by 4 and hence is the reqd answer

Should be D
Manager
Manager
avatar
Joined: 15 May 2014
Posts: 62
GMAT ToolKit User Premium Member
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 19 Apr 2015, 00:20
\(even\,*\,odd\,=\,even\)
\(even^2\,*\,odd^2\,=\,even*(even\,*odd\,*odd)\)\(\,=\,even\); resultant should be even
here \(225\) is the odd one out

Answer D
Director
Director
avatar
G
Joined: 21 May 2013
Posts: 651
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 19 Apr 2015, 03:22
1
[quote="Bunuel"]An even and an odd integer are multiplied together. Which of the following could not be the square of their product?

(A) 36
(B) 100
(C) 144
(D) 225
(E) 400

2*3=6 and 6^2=36
5*2=10 and 10^2=100
3*4=12 and 12^2=144
5*4=20 and 20^2=400

Answer D
Intern
Intern
User avatar
Joined: 29 Mar 2015
Posts: 1
Location: Japan
Concentration: International Business, Marketing
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 19 Apr 2015, 21:30
1
Hi Bunuel,

I think there might be a mistake here, the GMAT timer is showing C as the correct answer, is the answer not D?
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49892
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 20 Apr 2015, 05:08
Bunuel wrote:
An even and an odd integer are multiplied together. Which of the following could not be the square of their product?

(A) 36
(B) 100
(C) 144
(D) 225
(E) 400


Kudos for a correct solution.


VERITAS PREP OFFICIAL SOLUTION

One way to approach this problem is to start with an even and an odd integer and plug them in to the parameters set by the problem. If we begin with two and three, we see that the product is six and the square of the product is thirty six.

(2)(3) = 6; 6^2 = 36

Similarly we can see that two and five, three and four, and four and five all give us possible answer choices.

(2)(5) = 10; 10^2 = 100

(4)(3) = 12; 12^2 = 144

(4)(5) = 20; 20^2 = 400

Answer choice (D) is also a perfect square, but if we take the square root of it, we see that the result is fifteen, which is not divisible by an even and an odd number. Thus the only answer that could not be the squared product of an even and odd integer is answer choice (D).
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49892
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 20 Apr 2015, 05:09
1
Director
Director
User avatar
Joined: 07 Aug 2011
Posts: 540
Concentration: International Business, Technology
GMAT 1: 630 Q49 V27
GMAT ToolKit User
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 21 Apr 2015, 02:17
Bunuel wrote:
An even and an odd integer are multiplied together. Which of the following could not be the square of their product?

(A) 36
(B) 100
(C) 144
(D) 225
(E) 400


Kudos for a correct solution.


(A) 36 (1×6)^2
(B) 100 (1×10)^2
(C) 144 (1×12)^2
(D) 225(all factors are odd for this number , so this is our answer)
(E) 400(1×20)^2
_________________

Thanks,
Lucky

_______________________________________________________
Kindly press the Image to appreciate my post !! :-)

Intern
Intern
avatar
Joined: 20 Apr 2015
Posts: 7
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 26 Apr 2015, 22:07
Bunuel wrote:
achilds wrote:
Hi Bunuel,

I think there might be a mistake here, the GMAT timer is showing C as the correct answer, is the answer not D?


Yes, the correct answer is D. Edited the OA in the original post. Thank you for noticing this.



This can be simply be done in a sec, even * odd always gives even, and even square is even, except 225 rest all are even
Manager
Manager
avatar
G
Joined: 04 Jan 2016
Posts: 166
Location: United States (NY)
GMAT 1: 620 Q44 V32
GMAT 2: 600 Q48 V25
GMAT 3: 660 Q42 V39
GPA: 3.48
GMAT ToolKit User Premium Member
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 15 May 2017, 19:39
even times odd should give us even result.

The only add answer choice, 225, 15 times 15 is odd and it couldn't be the multiplication of and odd and an even number.
CEO
CEO
User avatar
P
Joined: 08 Jul 2010
Posts: 2530
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 15 May 2017, 21:35
Bunuel wrote:
An even and an odd integer are multiplied together. Which of the following could not be the square of their product?

(A) 36
(B) 100
(C) 144
(D) 225
(E) 400


Kudos for a correct solution.


(even*odd)^2 = ?

Checking options

(A) 36 = 2^2*3^2 possible
(B) 100 = 2^2*5^2 Possible
(C) 144 = 2^4*3^2 Possible
(D) 225 = 3^2*5^2 NOT Possible as no even power of 2 is available
(E) 400

Answer: Option D
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Retired Moderator
User avatar
P
Joined: 19 Mar 2014
Posts: 948
Location: India
Concentration: Finance, Entrepreneurship
GPA: 3.5
GMAT ToolKit User Premium Member
Re: An even and an odd integer are multiplied together. Which of the follo  [#permalink]

Show Tags

New post 15 May 2017, 22:18
Bunuel wrote:
An even and an odd integer are multiplied together. Which of the following could not be the square of their product?

(A) 36
(B) 100
(C) 144
(D) 225
(E) 400


Kudos for a correct solution.

Did not take much time, simply scanned the values as Even or Odd and there it was D.

Plugging numbers is a good way to cross check and still worth doing it considering scanning of numbers did not take much time.
_________________

"Nothing in this world can take the place of persistence. Talent will not: nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not: the world is full of educated derelicts. Persistence and determination alone are omnipotent."

Best AWA Template: https://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html#p470475

GMAT Club Bot
Re: An even and an odd integer are multiplied together. Which of the follo &nbs [#permalink] 15 May 2017, 22:18
Display posts from previous: Sort by

An even and an odd integer are multiplied together. Which of the follo

  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®.