It is currently 19 Nov 2017, 14:56

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

Events & Promotions in June
Open Detailed Calendar

an integer > 1 that is not prime is called composite. If

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 15 Aug 2006
Posts: 54

Kudos [?]: [0], given: 0

an integer > 1 that is not prime is called composite. If [#permalink]

Show Tags

New post 26 Nov 2006, 16:07
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

an integer > 1 that is not prime is called composite. If the 2 digit integer n is greater than 20, is n composite?

1. the ten digits of n is a factor of the units digit of n
2. the ten digit of n is 2.

Kudos [?]: [0], given: 0

Senior Manager
Senior Manager
avatar
Joined: 20 Feb 2006
Posts: 373

Kudos [?]: 37 [0], given: 0

 [#permalink]

Show Tags

New post 26 Nov 2006, 16:36
From 1) There are no prime numbers between 20 and 100 where the tens digit is a factor of the units digit therefore n must be composite. SUFF

From 2) n could be 23 and therefore prime or 24 and therefore composite so INSUFF.

A for me

Kudos [?]: 37 [0], given: 0

Manager
Manager
avatar
Joined: 24 Jun 2006
Posts: 60

Kudos [?]: 4 [0], given: 0

Answer is C [#permalink]

Show Tags

New post 26 Nov 2006, 19:24
I think Answer is C
For eg 13, The 10th place (1) is a factor of units place(3)
Statements 1 and 2 together give the answer

Kudos [?]: 4 [0], given: 0

VP
VP
User avatar
Joined: 25 Jun 2006
Posts: 1161

Kudos [?]: 203 [0], given: 0

 [#permalink]

Show Tags

New post 26 Nov 2006, 20:01
A for me too.

imagine the number is xy.
x >= 2, y > 0.

if x is a prime, then y must also be the same prime. so 11 is a factor.

if x is not a prime, then x has a factor which is also a factor of y. and hence a factor of this number xy.

so xy must have another factor other than itself and 1. so xy is a composite.


2. is Insuff. take 23. 24.

Kudos [?]: 203 [0], given: 0

Senior Manager
Senior Manager
avatar
Joined: 08 Jun 2006
Posts: 335

Kudos [?]: 63 [0], given: 0

Location: Washington DC
 [#permalink]

Show Tags

New post 26 Nov 2006, 23:44
This is a good one..
A for me too

Kudos [?]: 63 [0], given: 0

Manager
Manager
User avatar
Joined: 03 Jul 2005
Posts: 191

Kudos [?]: 12 [0], given: 0

Location: City
 [#permalink]

Show Tags

New post 27 Nov 2006, 00:35
an integer > 1 that is not prime is called composite. If the 2 digit integer n is greater than 20, is n composite?

1. the ten digits of n is a factor of the units digit of n
2. the ten digit of n is 2.

A?

From 1. 99 / 99 / 33 / 22 /66 etc.... meets the rule, the tens digit 9 is a factor of the units digit 9? But we cannot consider 13, since the integer is greater than 20. SUFF

From 2. n could be 24 (composite) or 23 (prime) INSUFF

Kudos [?]: 12 [0], given: 0

  [#permalink] 27 Nov 2006, 00:35
Display posts from previous: Sort by

an integer > 1 that is not prime is called composite. If

  post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderator: chetan2u



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