Find all School-related info fast with the new School-Specific MBA Forum

It is currently 29 Aug 2015, 09:05
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is x divisible by 30? (1) X = k*(m^3 - m), where m and k are

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
1 KUDOS received
SVP
SVP
User avatar
Joined: 05 Jul 2006
Posts: 1516
Followers: 5

Kudos [?]: 142 [1] , given: 39

GMAT ToolKit User
Is x divisible by 30? (1) X = k*(m^3 - m), where m and k are [#permalink] New post 10 Aug 2009, 09:57
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

50% (11:23) correct 50% (02:20) wrong based on 2 sessions
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Is x divisible by 30?

(1) X = k*(m^3 - m), where m and k are both integers > 9
(2) X = n^5 - n, where n is an integer > 9
Manager
Manager
avatar
Joined: 10 Jul 2009
Posts: 169
Followers: 1

Kudos [?]: 45 [0], given: 8

Re: divisibility - good one [#permalink] New post 10 Aug 2009, 10:06
1) X = k*(m^3 -m)
= K*m*(m-1)*(m+1)
Give K and m are > 9
X is definitely divisible by 2,3 but not by 5.
2)X = n^5 - n
= n*(n^4 - 1)
= n*(n^2 + 1)(n-1)(n + 1)
given n > 9
So for any value of n the value is divisible by 2,3,5.
Answer is B
Manager
Manager
avatar
Status: Applying
Joined: 18 Jul 2009
Posts: 155
Location: United Kingdom
Concentration: General Management, Strategy
GPA: 3.65
WE: Consulting (Telecommunications)
Followers: 1

Kudos [?]: 11 [0], given: 6

Re: divisibility - good one [#permalink] New post 10 Aug 2009, 21:53
thanks for the above answer but plz cud you explain how

n(n^2 + 1)(n+1)(n-1) is divisible by 5 ? Or is it a standard thing that i am missing ....

Thanks in advance....
1 KUDOS received
SVP
SVP
User avatar
Joined: 05 Jul 2006
Posts: 1516
Followers: 5

Kudos [?]: 142 [1] , given: 39

GMAT ToolKit User
Re: divisibility - good one [#permalink] New post 10 Aug 2009, 23:28
1
This post received
KUDOS
AshForGMAT wrote:
thanks for the above answer but plz cud you explain how

n(n^2 + 1)(n+1)(n-1) is divisible by 5 ? Or is it a standard thing that i am missing ....

Thanks in advance....


TRY PLUGING IN NUMBER ( N>9)... U WILL SEE FOR UR SELF
Director
Director
User avatar
Joined: 01 Apr 2008
Posts: 903
Schools: IIM Lucknow (IPMX) - Class of 2014
Followers: 18

Kudos [?]: 360 [0], given: 18

Re: divisibility - good one [#permalink] New post 15 Aug 2009, 12:17
Good one yezz +1. Keep them coming:)
Re: divisibility - good one   [#permalink] 15 Aug 2009, 12:17
Display posts from previous: Sort by

Is x divisible by 30? (1) X = k*(m^3 - m), where m and k are

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.