BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

If m is divisible by 3, how many

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 468
Joined: Mon Jul 25, 2011 10:20 pm
Thanked: 29 times
Followed by:4 members

If m is divisible by 3, how many

by vipulgoyal » Fri May 01, 2015 8:14 pm
If m is divisible by 3, how many prime factors does m have?

(1) m3 is divisible by 3

(2) m3 has two different prime factors

OA is C but I have the following query, experts plz

from 1&2 ;- m could be 3^2.2 or 3^2.2^2 in both cases ans will be different bcz stem is asking how many prime factors does m have? NOT how many different prime factors does m have?
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 43
Joined: Sat Mar 13, 2010 4:11 am
Thanked: 1 times

by STEVEN SPIELBERG » Sat May 02, 2015 2:21 am
vipulgoyal wrote:If m is divisible by 3, how many prime factors does m have?

(1) m3 is divisible by 3

(2) m3 has two different prime factors

OA is C but I have the following query, experts plz

from 1&2 ;- m could be 3^2.2 or 3^2.2^2 in both cases ans will be different bcz stem is asking how many prime factors does m have? NOT how many different prime factors does m have?
What is m3 ? Is it m^3 or m*3(m times 3) ?
I want to win an OSCAR on the GMAT !!!
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Sat May 02, 2015 3:12 am
On the GMAT, the question stem would make it clear that only DISTINCT prime factors of m should be considered.
The problem should read as follows:
vipulgoyal wrote:If m is divisible by 3, how many distinct prime factors does m have?

(1) m/3 is divisible by 3

(2) m/3 has two different prime factors
Statement 1: m/3 is divisible by 3
Case 1: m/3 = 3, implying that m=9.
In this case, m=3*3, with the result that m has 1 distinct prime factor.
Case 2: m/3 = 6, implying that m=18.
In this case, m=2*3*3, with the result that m has 2 distinct prime factors.
INSUFFICIENT.

Statement 2: m/3 has two different prime factors
Case 2: m/3 = 2*3, implying that m=2*3*3.
In this case, m has 2 distinct prime factors.
Case 3: m/3 = 2*5, implying that m=2*3*5
In this case, m has 3 distinct prime factors.
INSUFFICIENT.

Statements combined:
m/3 = (3^x)(p^y), where p is a prime number other than 3, and x and y are positive integers.
Since m = [ 3^(x+1) ](p^y), m has 2 distinct prime factors (3 and p).
SUFFICIENT.

The correct answer is C.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sat May 02, 2015 7:49 am
vipulgoyal wrote:If m is divisible by 3, how many prime factors does m have?

(1) m3 is divisible by 3

(2) m3 has two different prime factors
When posting questions, please take a moment to ensure that the posted question looks the same as the original question.
m3 could be interpreted as m³ or 3m.
Oddly enough, in this case, it means m/3

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Master | Next Rank: 500 Posts
Posts: 468
Joined: Mon Jul 25, 2011 10:20 pm
Thanked: 29 times
Followed by:4 members

by vipulgoyal » Sun May 03, 2015 10:15 am
Thanks Mitch/ Brent for prompt response , i really appreciate

having said that Q is not in proper format, I realized it at beginning , reason of posting, this q is entertained by one expert without ne doubt

https://gmatclub.com/forum/if-m-is-divis ... 96215.html

Brent thanks for adage, i"ll keep this in mind.
Top
GMAT Instructor
Posts: 2630
Joined: Wed Sep 12, 2012 3:32 pm
Location: East Bay all the way
Thanked: 625 times
Followed by:119 members
GMAT Score:780

by Matt@VeritasPrep » Sun May 03, 2015 10:07 pm
Brent@GMATPrepNow wrote: m3 could be interpreted as m³ or 3m.
Can 3m really be interpreted as m3? I'm not doubting you, I'm just curious what your source is - I find that notation hard to accept.
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Mon May 04, 2015 7:32 am
Matt@VeritasPrep wrote:
Brent@GMATPrepNow wrote: m3 could be interpreted as m³ or 3m.
Can 3m really be interpreted as m3? I'm not doubting you, I'm just curious what your source is - I find that notation hard to accept.
Well, my neighbor interprets m3 as 3m, as does my grandmother, and then there's that guy with the beard, and.......okay, you got me :-)
My pet peeve is forum posts where the poster hasn't bothered to confirm that things were posted correctly. Perhaps I went too far.
Standing down.... :-)

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1