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

It is currently 28 Aug 2015, 16:55
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

A number n has the prime factors a, b, and c, and only these

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 25 Jun 2012
Posts: 65
Followers: 0

Kudos [?]: 24 [0], given: 21

A number n has the prime factors a, b, and c, and only these [#permalink] New post 06 Nov 2012, 21:59
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

46% (02:11) correct 54% (01:12) wrong based on 26 sessions
A number n has the prime factors a, b, and c, and only these prime factors. Can n be factored as ab^2c^2?

(1) n is a multiple of ab

(2) n contains exactly 5 factors.
[Reveal] Spoiler: OA
Manager
Manager
avatar
Joined: 27 Feb 2012
Posts: 138
Followers: 1

Kudos [?]: 33 [0], given: 22

Re: A number n has the prime factors a, b, and c, and only these [#permalink] New post 06 Nov 2012, 22:13
actleader wrote:
A number n has the prime factors a, b, and c, and only these prime factors. Can n be factored as ab^2c^2?

(1) n is a multiple of ab

(2) n contains exactly 5 factors.

(A) Statement (1) ALONE is sufficient, but statement (2) is not sufficient.
(B) Statement (2) ALONE is sufficient, but statement (1) is not sufficient.
(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(D) EACH statement ALONE is sufficient.
(E) Statements (1) and (2) TOGETHER are NOT sufficient.


Can you clarify the question stem?
n be factored as ab^2c^2
is it ab*2c*2 ?
_________________

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Please +1 KUDO if my post helps. Thank you.

Manager
Manager
avatar
Joined: 25 Jun 2012
Posts: 65
Followers: 0

Kudos [?]: 24 [0], given: 21

Re: A number n has the prime factors a, b, and c, and only these [#permalink] New post 07 Nov 2012, 12:11
BangOn wrote:
actleader wrote:
A number n has the prime factors a, b, and c, and only these prime factors. Can n be factored as ab^2c^2?

(1) n is a multiple of ab

(2) n contains exactly 5 factors.

(A) Statement (1) ALONE is sufficient, but statement (2) is not sufficient.
(B) Statement (2) ALONE is sufficient, but statement (1) is not sufficient.
(C) BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
(D) EACH statement ALONE is sufficient.
(E) Statements (1) and (2) TOGETHER are NOT sufficient.


Can you clarify the question stem?
n be factored as ab^2c^2
is it ab*2c*2 ?



Hi, sorry for question posted not quite understandably.
\(ab^2c^2\)
1 KUDOS received
Senior Manager
Senior Manager
User avatar
Joined: 19 Apr 2009
Posts: 435
Location: San Francisco, California
Followers: 77

Kudos [?]: 284 [1] , given: 5

Re: A number n has the prime factors a, b, and c, and only these [#permalink] New post 07 Nov 2012, 13:37
1
This post received
KUDOS
This is a poorly written question, and there are several mistakes.

If a, b, and c are the prime factors of n, then we know that at the very least n must have 8 factors, inclusive of 1 and n. This is because if n = abc, then the number of factors is equal to (1+1)(1+1)(1+1) = 8, essentially add 1 to the powers of all the primes in the factorization and multiply them. I won't go over why that is the case, but that is an important concept to understand. Here statement 2 contradicts this condition and says n has 5 factors.

Also, in a real GMAT question the writers will always clarify and say that n has five factors, inclusive of 1 and n.

Here are few examples of similar questions that are actual GMAT questions, and I would say your valuable time is better spent on these.
I know there are so many problems here and sorting through what is useful and what is not is indeed a daunting task.

1) how-many-different-prime-numbers-are-factors-of-the-positive-126744.html
2) in-n-is-a-positive-integer-less-than-200-and-14n-60-is-an-81459.html
3) if-the-prime-numbers-p-and-t-are-the-only-prime-factors-of-85836.html
4) how-many-different-factors-does-the-integer-n-have-1-n-47115.html
5) if-p-s-and-t-are-positive-prime-numbers-what-is-the-value-78410.html

Cheers,
Dabral
_________________

New!2016 OFFICIAL GUIDE FOR GMAT REVIEW: Free Video Explanations.
http://www.gmatquantum.com

Re: A number n has the prime factors a, b, and c, and only these   [#permalink] 07 Nov 2012, 13:37
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic If each of the positive integers a, b, and c is a prime number and abc Bunuel 3 17 Dec 2014, 06:50
How many prime factors does N have? shivanigs 7 06 Oct 2012, 00:31
4 Experts publish their posts in the topic If n is a whole number, is n + 1 a prime number? shekar123 2 01 Jun 2010, 18:44
20 Experts publish their posts in the topic If the prime numbers p and t are the only prime factors of phoenixgmat 21 26 Oct 2009, 13:53
10 Experts publish their posts in the topic If the prime numbers p and t are the only prime factors of gulatin2 10 19 Aug 2009, 10:55
Display posts from previous: Sort by

A number n has the prime factors a, b, and c, and only these

  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®.