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

It is currently 12 Dec 2018, 13:30

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
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • The winning strategy for 700+ on the GMAT

     December 13, 2018

     December 13, 2018

     08:00 AM PST

     09:00 AM PST

    What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.
  • GMATbuster's Weekly GMAT Quant Quiz, Tomorrow, Saturday at 9 AM PST

     December 14, 2018

     December 14, 2018

     09:00 AM PST

     10:00 AM PST

    10 Questions will be posted on the forum and we will post a reply in this Topic with a link to each question. There are prizes for the winners.

If x and y are different prime numbers, each greater than 2, which of

  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: 51121
If x and y are different prime numbers, each greater than 2, which of  [#permalink]

Show Tags

New post 17 Feb 2016, 03:38
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

83% (00:36) correct 17% (00:35) wrong based on 186 sessions

HideShow timer Statistics

If x and y are different prime numbers, each greater than 2, which of the following must be true?

I. x+y is an even integer

II. xy is an odd integer

III. (x/y) is not an integer

A. II only
B. I and II only
C. I and III only
D. II and III only
E. I, II, and III


Kudos for 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

Senior Manager
Senior Manager
User avatar
Joined: 20 Aug 2015
Posts: 390
Location: India
GMAT 1: 760 Q50 V44
If x and y are different prime numbers, each greater than 2, which of  [#permalink]

Show Tags

New post 23 Feb 2016, 02:42
1
Bunuel wrote:
If x and y are different prime numbers, each greater than 2, which of the following must be true?

I. x+y is an even integer
II. xy is an odd integer
III. (x/y) is not an integer

A. II only
B. I and II only
C. I and III only
D. II and III only
E. I, II, and III

Kudos for correct solution.


This question tests your knowledge about the effect of addition and multiplication on odd and even numbers:
Even + Even = Even
Odd + Even = Odd
Odd + Odd = Even

Even * Even = Even
Odd * Even = Even
Odd * Odd = Odd


Given: x and y are different prime numbers, both greater than 2

Statement I: x+y is an even integer
Since x and y are prime numbers greater than 2, they will be odd
Therefore sum will be even.
Correct

Statement II: xy is an odd integer
Since x and y are prime numbers greater than 2, they will be odd
Therefore multiplication will be odd.
Correct

Statement III: (x/y) is not an integer
Since x and y are prime integers, therefore they will not have any common factor apart from 1
Hence (x/y) will not be an integer
Correct

Hence all three statements I, II and III are correct
Option E
Current Student
avatar
B
Status: Persevere
Joined: 08 Jan 2016
Posts: 119
Location: Hong Kong
GMAT 1: 750 Q50 V41
GPA: 3.52
Reviews Badge
Re: If x and y are different prime numbers, each greater than 2, which of  [#permalink]

Show Tags

New post 24 Feb 2016, 02:25
1
1
Bunuel wrote:
If x and y are different prime numbers, each greater than 2, which of the following must be true?

I. x+y is an even integer

II. xy is an odd integer

III. (x/y) is not an integer

A. II only
B. I and II only
C. I and III only
D. II and III only
E. I, II, and III

Kudos for correct solution.


\(x\) and \(y\) are different prime numbers, each greater than 2.
As 2 is the only even prime number, both \(x\) and \(y\) must be odd.
So, we have three properties that will be useful in solving this question:
1. \(x\) and \(y\) are prime numbers
2. \(x\) and \(y\) are odd numbers
3. \(x\) and \(y\) are different numbers

Now, let us consider each statement.
Statement I: \(x + y\) is an even integer
We know that both \(x\) and \(y\) are odd. We also know that odd + odd = even
hence, \(x + y\) is an even integer.
So, statement I must be true.

Statement II: \(xy\) is an odd integer
We know that both \(x\) and \(y\) are odd. We also know that odd x odd = odd
hence, \(xy\) is an odd integer.
So, statement II must also be true.

Statement III: \(x/y\) is not an integer
This could have been tricky. But we know that \(x\) and \(y\) are different numbers. So, \(x/y\) cannot be 1. We also know that \(x\) and \(y\) are prime numbers. So, \(x\) is definitely not divisible by \(y\).
Hence, \(x/y\) cannot be an integer.
So, statement III must also be true.

Therefore, the correct answer is E.
Intern
Intern
avatar
B
Joined: 26 Jul 2016
Posts: 39
Location: India
Re: If x and y are different prime numbers, each greater than 2, which of  [#permalink]

Show Tags

New post 26 May 2017, 02:59
Primes greater than 2 are odd nos.
1. odd+odd= even
2. odd*odd= odd
3. prime/prime= not integer

Hence option E.
EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 13064
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: If x and y are different prime numbers, each greater than 2, which of  [#permalink]

Show Tags

New post 27 Sep 2018, 19:22
Hi All,

We're told that a X and Y are DIFFERENT PRIME numbers, each GREATER than 2. We're asked which of the following must be true (which really means "which of these is ALWAYS true no matter how many different examples you can come up with?"). This question can be solved used Number Properties and a bit of logic.

I. X + Y is an EVEN integer

Since X and Y are PRIME numbers AND they're both greater than 2, they must both be ODD numbers.
Odd + Odd = ALWAYS Even, so Roman Numeral 1 is always true.
Eliminate Answers A and D.

II. (X)(Y) is an ODD integer

We already know that X and Y are both ODD numbers.
(Odd)(Odd) = ALWAYS Odd, so Roman Numeral 2 is always true.
Eliminate Answer C.

III. (X/Y) is NOT an integer

For X/Y to be an integer, X must be a MULTIPLE of Y. We're told that X and Y are DIFFERENT numbers - and by definition, a PRIME number has no other factors besides 1 and itself, so it is NOT possible for X to be a multiple of Y. Thus, X/Y will NEVER be an integer under these circumstances and Roman Numeral 3 is always true.
Eliminate Answer B.

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!*****

GMAT Club Bot
Re: If x and y are different prime numbers, each greater than 2, which of &nbs [#permalink] 27 Sep 2018, 19:22
Display posts from previous: Sort by

If x and y are different prime numbers, each greater than 2, which of

  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®.