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

It is currently 21 Oct 2018, 20:42

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 the average (arithmetic mean) of positive integers x and y is a pos

  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: 50009
If the average (arithmetic mean) of positive integers x and y is a pos  [#permalink]

Show Tags

New post 08 Jan 2018, 23:40
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

49% (01:48) correct 51% (01:53) wrong based on 81 sessions

HideShow timer Statistics

If the average (arithmetic mean) of positive integers x and y is a positive integer, is it prime?

(1) The average (arithmetic mean) of 3x and 3y is 12.
(2) The sum of x and y is divisible by 4.

_________________

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

DS Forum Moderator
avatar
P
Joined: 22 Aug 2013
Posts: 1348
Location: India
Premium Member
Re: If the average (arithmetic mean) of positive integers x and y is a pos  [#permalink]

Show Tags

New post 09 Jan 2018, 04:11
1
Bunuel wrote:
If the average (arithmetic mean) of positive integers x and y is a positive integer, is it prime?

(1) The average (arithmetic mean) of 3x and 3y is 12.
(2) The sum of x and y is divisible by 4.


Average of x and y = (x+y)/2 = z (say, where z is a positive integer). We have to answer whether z is prime or not.

(1) Given, (3x + 3y)/2 = 12 or 3x + 3y = 24 or (x+y) = 8. So we can find z, so we will be able to decipher whether z is prime or not. Sufficient.

(2) Sum of x+y could be 4 or 8 or 12 or 16 etc...
So z could be 2 or 4 or 6 etc.. so it could be prime (2) or it might not be (4, 6 etc). So Insufficient.

Hence A answer
Intern
Intern
avatar
B
Joined: 29 Aug 2017
Posts: 26
Re: If the average (arithmetic mean) of positive integers x and y is a pos  [#permalink]

Show Tags

New post 11 Feb 2018, 04:28
1
Bunuel wrote:
If the average (arithmetic mean) of positive integers x and y is a positive integer, is it prime?

(1) The average (arithmetic mean) of 3x and 3y is 12.
(2) The sum of x and y is divisible by 4.



Hey Shouldn't the answer be A, Please confirm- as option B) has two possibilities (2-which is prime) and 4,6,8(non-primes)
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50009
Re: If the average (arithmetic mean) of positive integers x and y is a pos  [#permalink]

Show Tags

New post 11 Feb 2018, 08:21
PearlRay wrote:
Bunuel wrote:
If the average (arithmetic mean) of positive integers x and y is a positive integer, is it prime?

(1) The average (arithmetic mean) of 3x and 3y is 12.
(2) The sum of x and y is divisible by 4.



Hey Shouldn't the answer be A, Please confirm- as option B) has two possibilities (2-which is prime) and 4,6,8(non-primes)


Yes, the answer is A, not D. Edited. Thank you.
_________________

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

GMAT Club Bot
Re: If the average (arithmetic mean) of positive integers x and y is a pos &nbs [#permalink] 11 Feb 2018, 08:21
Display posts from previous: Sort by

If the average (arithmetic mean) of positive integers x and y is a pos

  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®.