Last visit was: 10 Jul 2025, 13:35 It is currently 10 Jul 2025, 13:35
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
User avatar
megafan
Joined: 28 May 2009
Last visit: 15 Oct 2017
Posts: 137
Own Kudos:
923
 [26]
Given Kudos: 91
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03-22-2013
GPA: 3.57
WE:Information Technology (Consulting)
Posts: 137
Kudos: 923
 [26]
6
Kudos
Add Kudos
19
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 10 Jul 2025
Posts: 16,101
Own Kudos:
74,246
 [13]
Given Kudos: 475
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,101
Kudos: 74,246
 [13]
10
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
General Discussion
User avatar
sambam
Joined: 18 Oct 2011
Last visit: 09 Jan 2014
Posts: 58
Own Kudos:
402
 [2]
Location: United States
Concentration: Entrepreneurship, Marketing
GMAT Date: 01-30-2013
GPA: 3.3
Posts: 58
Kudos: 402
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
BangOn
Joined: 27 Feb 2012
Last visit: 22 Mar 2019
Posts: 95
Own Kudos:
Given Kudos: 22
Posts: 95
Kudos: 187
Kudos
Add Kudos
Bookmarks
Bookmark this Post
megafan
If k is a multiple of 3 and \(k = (m^2)n\), where m and n are prime numbers, which of the following must be a multiple of 9?

(A) \(m^2\)
(B) \(n^2\)
(C) \(mn\)
(D) \(mn^2\)
(E) \((mn)^2\)

Source: Gmat Hacks 1800


must be a multiple of 9
m and n are prime...lets have 2 and 3
now either of then can be a 3...
a) m can be 2 and n = 3...out
b) n can be 2 and m = 3...out
c) m = 2 and n=3 ...out
d) n can be 2 and m = 3...out
e) m = 2/3 or n = 3/2 both satisfies .......must be a multiple of 9
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: -
Posts: 102,624
Own Kudos:
740,168
 [1]
Given Kudos: 98,170
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,624
Kudos: 740,168
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
megafan
If k is a multiple of 3 and \(k = (m^2)n\), where m and n are prime numbers, which of the following must be a multiple of 9?

(A) \(m^2\)
(B) \(n^2\)
(C) \(mn\)
(D) \(mn^2\)
(E) \((mn)^2\)

Source: Gmat Hacks 1800

This question is almost exact copy of the following GMAT Prep question: if-is-n-is-multiple-of-5-and-n-p-2-q-where-p-and-q-are-prim-92383.html
avatar
sahniminie
Joined: 20 Sep 2016
Last visit: 19 Dec 2016
Posts: 1
Posts: 1
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Either m or n is 3,
so "E" is correct
avatar
Akuthiala
Joined: 23 Jun 2016
Last visit: 18 Oct 2016
Posts: 34
Own Kudos:
Given Kudos: 13
Posts: 34
Kudos: 10
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A) No since n could be 9
B) No since m=3
C) No since m could be 2 and n=3
D) No since M could 3 and n=2
E) Yes since either M or N have to be 3 (or factor) so they will become a factor of 9
User avatar
BrushMyQuant
Joined: 05 Apr 2011
Last visit: 10 Jul 2025
Posts: 2,243
Own Kudos:
Given Kudos: 100
Status:Tutor - BrushMyQuant
Location: India
Concentration: Finance, Marketing
Schools: XLRI (A)
GMAT 1: 700 Q51 V31
GPA: 3
WE:Information Technology (Computer Software)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Schools: XLRI (A)
GMAT 1: 700 Q51 V31
Posts: 2,243
Kudos: 2,458
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If k is a multiple of 3 and \(k = (m^2)n\) then \((m^2)n\) will also be a multiple of 3

Since both m and n are prime numbers, so either m is 3 or n is 3 or both are 3
In any case, m*n will be a multiple of 3
=> \((mn)^2\) will be a multiple of \(3^2\) or 9

So, \(Answer will be E\)
Hope it helps!
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 37,379
Own Kudos:
Posts: 37,379
Kudos: 1,010
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderators:
Math Expert
102624 posts
PS Forum Moderator
685 posts