GMATPrep2: Multiple of prime factors : DS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 17 Jan 2017, 14:24

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

GMATPrep2: Multiple of prime factors

Author Message
Manager
Joined: 20 Aug 2009
Posts: 107
Followers: 2

Kudos [?]: 118 [0], given: 31

GMATPrep2: Multiple of prime factors [#permalink]

Show Tags

03 Sep 2009, 02:36
00:00

Difficulty:

(N/A)

Question Stats:

33% (04:54) correct 67% (02:35) wrong based on 2 sessions

HideShow timer Statistics

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

Don't know how to approach the first statement..

OA
[Reveal] Spoiler:
B
Current Student
Affiliations: ?
Joined: 20 Jul 2009
Posts: 191
Location: Africa/Europe
Schools: Kellogg; Ross (); Tuck
Followers: 2

Kudos [?]: 33 [1] , given: 6

Re: GMATPrep2: Multiple of prime factors [#permalink]

Show Tags

03 Sep 2009, 06:40
1
KUDOS
m can be written as this:
m = $$p^x$$*$$t^y$$ where x and y are positives integers. (this is the decomposition of m as product of primes factors)

The question is asking if $$x>=2$$?

1) from this stament we can say that x+y > 9 : not sufficient

2) from this one: x > 3 sufficient
Manager
Joined: 10 Aug 2009
Posts: 130
Followers: 3

Kudos [?]: 67 [0], given: 10

Re: GMATPrep2: Multiple of prime factors [#permalink]

Show Tags

03 Sep 2009, 06:56
Since p and t are the only primes,
$$m=p^it^j$$ where j>=1 and i>=1
If m is a multiple of $$p^2t$$, i>=2 and j>=1. Since we know that j>=1, we have only to prove that i>=2.

Statement 1

$$i\times j+1>9$$(note that generally the formula for the number of primes is (j+1)(i+1) but since we can elimintae all cases with i=0 or j=0, the formula is i\times j+1...1 is added since the case j=0 and i=0 can never eliminted )

Not sufficent
consider the case i=1 and j=9...not a multiple of p^2t

Statemet 2
sufficient since i=3 and $$m=p^3t^j$$ where j>=1.
Manager
Joined: 25 Aug 2009
Posts: 176
Followers: 1

Kudos [?]: 89 [0], given: 12

Re: GMATPrep2: Multiple of prime factors [#permalink]

Show Tags

03 Sep 2009, 15:02
m can be written as this:
m = $$p^x$$*$$t^y$$ where x and y are positives integers. (this is the decomposition of m as product of primes factors)

The question is asking if $$x>=2$$?

1) from this stament we can say that x+y > 9 : not sufficient

2) from this one: x > 3 sufficient

I liked the approach..good one..
Re: GMATPrep2: Multiple of prime factors   [#permalink] 03 Sep 2009, 15:02
Display posts from previous: Sort by
{"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}