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

It is currently 24 Aug 2016, 02:06
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

Modulus

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Director
Director
avatar
Joined: 12 Oct 2008
Posts: 554
Followers: 3

Kudos [?]: 343 [0], given: 2

Modulus [#permalink]

Show Tags

New post 28 Oct 2009, 16:40
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

50% (00:00) correct 50% (01:42) wrong based on 1 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If n is a positive integer, which of the following is a possible value of |56 - 5n|?
A. 7
B. 9
C. 12
D. 15
E. 20

[Reveal] Spoiler:
OA B, am I suppose to expand the equation? \((56-5n)^2\)
SVP
SVP
User avatar
Joined: 29 Aug 2007
Posts: 2492
Followers: 66

Kudos [?]: 692 [0], given: 19

Re: Modulus [#permalink]

Show Tags

New post 28 Oct 2009, 19:35
reply2spg wrote:
If n is a positive integer, which of the following is a possible value of |56 - 5n|?

A. 7
B. 9
C. 12
D. 15
E. 20

[Reveal] Spoiler:
OA B, am I suppose to expand the equation? \((56-5n)^2\)


= |56 - 5n|
= |(10*5) +1 - 5n|

Since n is a +ve integer, |56 - 5n| must end in either (5k + 4) or (5k - 4) or (5k + 1) or (5k - 1). Only 9 fits to the formats above. So its B.
_________________

Verbal: http://gmatclub.com/forum/new-to-the-verbal-forum-please-read-this-first-77546.html
Math: http://gmatclub.com/forum/new-to-the-math-forum-please-read-this-first-77764.html
Gmat: http://gmatclub.com/forum/everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

Senior Manager
Senior Manager
User avatar
Joined: 18 Aug 2009
Posts: 303
Followers: 3

Kudos [?]: 229 [0], given: 9

Re: Modulus [#permalink]

Show Tags

New post 28 Oct 2009, 22:46
so confused with this :)
this is the best I could come up with after a coffee:

possibilities for units digit:
6-5 = 1
6-0 = 6
reversing the subtraction (as it is absolute)
5-6 = -1
15-6 = 9
10-6 = 4

only one answer option, 9, fits above
prove using -56+5(12) = -56+65 = 9
Manager
Manager
avatar
Joined: 15 Sep 2009
Posts: 137
Followers: 1

Kudos [?]: 22 [0], given: 2

Re: Modulus [#permalink]

Show Tags

New post 29 Oct 2009, 04:48
Try substituting values for n and we will end with 9.

n = 13 ==> | 56-65| ==> 9

I will choose option B
Senior Manager
Senior Manager
avatar
Joined: 16 Jul 2009
Posts: 261
Followers: 5

Kudos [?]: 262 [0], given: 3

Re: Modulus [#permalink]

Show Tags

New post 31 Oct 2009, 11:44
Substituting the values is the best approach.. and leads to option B, which is correct answer.
Re: Modulus   [#permalink] 31 Oct 2009, 11:44
Display posts from previous: Sort by

Modulus

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| 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®.