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

It is currently 25 Oct 2014, 06:52

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

confusing ONE

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Current Student
User avatar
Joined: 11 May 2008
Posts: 559
Followers: 7

Kudos [?]: 34 [0], given: 0

confusing ONE [#permalink] New post 08 Aug 2008, 08:59
guys ...i just didnt get this problem.... pls can some one tell me what exactly is being asked?? and how to start analysis of such problems... also what difficulty level is this problem at? on a scale of 1 to 5? 5 being most difficult...

and what is the meaning of sentence 1?? it says m has 9 +ve factors. in the stem it says m has 2 prime factors... how can a no. have factors like this??
is it that square and cube of the basic prime nos are also considered??
how do we start thinking abt such problems on the exam day???

:( :( :( :!: :!: :!: :!: :!: :x :x :roll:
Attachments

prime.doc [69 KiB]
Downloaded 78 times

To download please login or register as a user

1 KUDOS received
Director
Director
avatar
Joined: 10 Sep 2007
Posts: 950
Followers: 7

Kudos [?]: 189 [1] , given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:10
1
This post received
KUDOS
Question says M = p^xt^y. Given Atleast x=1, and y=1.
Question is asking is x>=2, Already given t is a factor so we are not bother about it.

1) Says m has 9 factor may be x=1 and t=8, or x=8 and t=1. This is may be case so question cannot be answered and A, D out.

2) Tells us x=3. So question is answered. Answer B.
Current Student
User avatar
Joined: 11 May 2008
Posts: 559
Followers: 7

Kudos [?]: 34 [0], given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:15
well, does'nt look like it is asking that.. it asks if m is divisible by p^2*t. i dont think that is the same thing as is power of p>=2.... right??? or.... wrong :roll:

what it looks to be asking is when m/p^2*t, do we get an integer???
but i think that if p and t divide m , then p^2 usually divides right, unless the m itself <p^2*t.
eg , take 6. it is divisible by 2 and 3 , but not by 2^2*3, but that is bcos p^2*t>m for this example... but what is the problem asking us?
Senior Manager
Senior Manager
avatar
Joined: 23 May 2006
Posts: 328
Followers: 2

Kudos [?]: 79 [0], given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:19
Good explanation.
Director
Director
avatar
Joined: 10 Sep 2007
Posts: 950
Followers: 7

Kudos [?]: 189 [0], given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:20
arjtryarjtry wrote:
well, does'nt look like it is asking that.. it asks if m is divisible by p^2*t. i dont think that is the same thing as is power of p>=2.... right??? or.... wrong :roll:


I have rephrased the question. Thereby it looks different. If M is divisible by p^2t then of course it means that m has factor of p equal to or more than 2 and also that m has a factor of t.
CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2500
Followers: 54

Kudos [?]: 512 [0], given: 19

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:25
arjtryarjtry wrote:
guys ...i just didnt get this problem.... pls can some one tell me what exactly is being asked?? and how to start analysis of such problems... also what difficulty level is this problem at? on a scale of 1 to 5? 5 being most difficult...

and what is the meaning of sentence 1?? it says m has 9 +ve factors. in the stem it says m has 2 prime factors... how can a no. have factors like this??
is it that square and cube of the basic prime nos are also considered??
how do we start thinking abt such problems on the exam day???

:( :( :( :!: :!: :!: :!: :!: :x :x :roll:



1: to have more than 9 +ve factors, either, at least, p = 4 and t = 1, or p = 1 and t = 4. nsf.
2: m is a multiple of p^3 means m is also a multiple of p^2t. suff

So B.
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2500
Followers: 54

Kudos [?]: 512 [0], given: 19

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:27
abhijit_sen wrote:
arjtryarjtry wrote:
well, does'nt look like it is asking that.. it asks if m is divisible by p^2*t. i dont think that is the same thing as is power of p>=2.... right??? or.... wrong :roll:


I have rephrased the question. Thereby it looks different. If M is divisible by p^2t then of course it means that m has factor of p equal to or more than 2 and also that m has a factor of t.


That could be a question, but GMAT questions donot have that pattern.

it is: is m/[(p^2)(t)] = k?
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

Director
Director
avatar
Joined: 27 May 2008
Posts: 552
Followers: 5

Kudos [?]: 178 [0], given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:39
one important formula to know

if m can be written as m = p^x * q^y * r ^z where p, q and r are distinct prime numbers
number for total +ve factors = (1+x)(1+y)(1+z)

question : m = p^x * t^y
is m a mutiple of p^2 * t --> is x >=2

statement 1 : (1+x)(1+y) > 9 .... x,y = 1,4 Or 3,3 Not suff
statement 2 : m = k * p^3 ----> x >=3 .. Suff
Current Student
User avatar
Joined: 11 May 2008
Posts: 559
Followers: 7

Kudos [?]: 34 [0], given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:49
durgesh79 wrote:
one important formula to know

if m can be written as m = p^x * q^y * r ^z where p, q and r are distinct prime numbers
number for total +ve factors = (1+x)(1+y)(1+z)

question : m = p^x * t^y
is m a mutiple of p^2 * t --> is x >=2

statement 1 : (1+x)(1+y) > 9 .... x,y = 1,4 Or 3,3 Not suff
statement 2 : m = k * p^3 ----> x >=3 .. Suff


why this combination?? how did u arrive at that combo of 1,4 or 3,3? why not 2,5 or something like that?
Director
Director
avatar
Joined: 27 May 2008
Posts: 552
Followers: 5

Kudos [?]: 178 [0], given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 09:53
arjtryarjtry wrote:
durgesh79 wrote:
one important formula to know

if m can be written as m = p^x * q^y * r ^z where p, q and r are distinct prime numbers
number for total +ve factors = (1+x)(1+y)(1+z)

question : m = p^x * t^y
is m a mutiple of p^2 * t --> is x >=2

statement 1 : (1+x)(1+y) > 9 .... x,y = 1,4 Or 3,3 Not suff
statement 2 : m = k * p^3 ----> x >=3 .. Suff


why this combination?? how did u arrive at that combo of 1,4 or 3,3? why not 2,5 or something like that?


we have to see if (1+x)(1+y) > 9 is enough to prove that x >= 2 or not , so i took two examples with x < 2 and x > 2. Since both cases are possible, the statement is not suff.
VP
VP
avatar
Joined: 17 Jun 2008
Posts: 1406
Followers: 7

Kudos [?]: 122 [0], given: 0

Re: confusing ONE [#permalink] New post 08 Aug 2008, 10:08
arjtryarjtry wrote:
guys ...i just didnt get this problem.... pls can some one tell me what exactly is being asked?? and how to start analysis of such problems... also what difficulty level is this problem at? on a scale of 1 to 5? 5 being most difficult...

and what is the meaning of sentence 1?? it says m has 9 +ve factors. in the stem it says m has 2 prime factors... how can a no. have factors like this??
is it that square and cube of the basic prime nos are also considered??
how do we start thinking abt such problems on the exam day???

:( :( :( :!: :!: :!: :!: :!: :x :x :roll:


given that :
Only two prime factors are p,t of m
question : m=p^2 * t *n n is any integer
n is again product of p,t only since p,t are only prime factors

(1) says m has > 9 positive factors => t^8.p or p^8.t or t^2*p^7
etc
hence when m=p*t^8 then its not the multiple of p^2 *t
when m = p^8.t then its the multiple of p^2 *t
INSUFFI

(2) says m is multiple of p^3 also only two prime factors of m are p,t
hence p^3 * p^k * t^l is possible hence always multiple of p^2*t

SUFFI
IMO B
_________________

cheers
Its Now Or Never

Intern
Intern
avatar
Joined: 06 Aug 2008
Posts: 2
Followers: 0

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

Re: confusing ONE [#permalink] New post 08 Aug 2008, 19:36
I will first take the example and then i will explain it...
Say m = 36. So m has 9 factors: 1 2 3 4 6 9 12 18 36.
Now only two numbers are prime in this: 2 and 3. say p and t.
so p^2*t^2 = m.
so, A is definately the answer, because p^2 *t is factor of m, obviously.

Further, in general, we have (a + 1)(b+1)(c+1) factors of a number where a, b, c are powers of prime number in the factors of number....

see, example, 36 has 9 factors....(3)(3)=9. so a = 2, b = 2. because there are only two primes 2, 3.

So clearly A is the answer. Not B.
Senior Manager
Senior Manager
avatar
Joined: 06 Apr 2008
Posts: 452
Followers: 1

Kudos [?]: 51 [0], given: 1

Re: confusing ONE [#permalink] New post 08 Aug 2008, 22:38
arjtryarjtry wrote:
guys ...i just didnt get this problem.... pls can some one tell me what exactly is being asked?? and how to start analysis of such problems... also what difficulty level is this problem at? on a scale of 1 to 5? 5 being most difficult...

and what is the meaning of sentence 1?? it says m has 9 +ve factors. in the stem it says m has 2 prime factors... how can a no. have factors like this??
is it that square and cube of the basic prime nos are also considered??
how do we start thinking abt such problems on the exam day???

:( :( :( :!: :!: :!: :!: :!: :x :x :roll:


It is B)

Suppose there is a number 12, now it has only two prime factors 2 and 3

Statement 1) is insuff. because you can have 3^9*2 and it is not multiple of 2^2 * 3
Statement 2) if m is multiple of p^3 then it will be multiple of p^2 as well and t is already another prime factor so multiple of p^2 * t
Re: confusing ONE   [#permalink] 08 Aug 2008, 22:38
    Similar topics Author Replies Last post
Similar
Topics:
11 Experts publish their posts in the topic One-Singular or Plural confusion/massacre One of the major souvik101990 10 18 Sep 2012, 11:50
Experts publish their posts in the topic Confusing One.. sahilkhurana06 2 11 Sep 2010, 22:00
confusing one atletikos 15 23 Nov 2008, 04:28
This one is confusing. Need some detailed explaination. alimad 4 11 Jun 2008, 10:01
I am confused about this one.... Temperature measurements FN 5 27 Jul 2005, 18:16
Display posts from previous: Sort by

confusing ONE

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.