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

 It is currently 06 May 2015, 14:47

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

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If N is a positive integer and N^2 is divisible by 72, then

Author Message
TAGS:
Manager
Joined: 29 May 2007
Posts: 97
Followers: 2

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

If N is a positive integer and N^2 is divisible by 72, then [#permalink]  09 Aug 2007, 17:17
If N is a positive integer and N^2 is divisible by 72, then the largest positive integer that must divide N is:

a)6
b)12
c)24
d)36
e)48

Director
Joined: 12 Jul 2007
Posts: 865
Followers: 12

Kudos [?]: 218 [0], given: 0

search through the first 1 or 2 pages, this question was just asked recently.

if I remember correctly the answer is B. 12 and they had plenty of explanation to go along with it.
Director
Joined: 03 May 2007
Posts: 894
Schools: University of Chicago, Wharton School
Followers: 6

Kudos [?]: 63 [0], given: 7

Re: GMAT Review [#permalink]  09 Aug 2007, 18:53
r0m3416 wrote:
If N is a positive integer and N^2 is divisible by 72, then the largest positive integer that must divide N is:

a)6
b)12
c)24
d)36
e)48

B. 12

n^2 = 72k
n^2 = 2x2x2x3x3 (k)

since n is a +ve integer and n^2 is a square, 72k has to be a squre. if so, then k should be at least 2. in that case n = 2x2x3 = 12.
Director
Joined: 09 Aug 2006
Posts: 766
Followers: 1

Kudos [?]: 69 [0], given: 0

Re: GMAT Review [#permalink]  10 Aug 2007, 00:34
r0m3416 wrote:
If N is a positive integer and N^2 is divisible by 72, then the largest positive integer that must divide N is:

a)6
b)12
c)24
d)36
e)48

Since N^2 is divisible by 72, N^2 is atleast 72*2=144 implying that N has to be atleast 12. Answer B.
Intern
Joined: 03 Aug 2007
Posts: 3
Followers: 0

Kudos [?]: 1 [0], given: 0

I think that the answer is d (36),
because 36^2 = 1296, it divides 72!
If that is not correct, please tell

it cannot be E, because 48, as 42^2 =1764, does not divide 72...
Similar topics Replies Last post
Similar
Topics:
If n is a positive integer and n^2 is divisible by 72, then 16 08 Jan 2007, 23:21
2 If n is a positive integer and n^2 is divisible by 72, then 10 16 Sep 2006, 09:57
If n is a positive integer and n^2 is divisible by 72, then 2 15 Apr 2006, 20:03
If n is a positive integer and n^2 is divisible by 72, then 1 12 Dec 2005, 22:51
If n is a positive integer and n^2 is divisible by 72, then 3 07 Oct 2005, 02:51
Display posts from previous: Sort by