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

It is currently 20 Aug 2014, 12:42

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

factor

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
SVP
SVP
avatar
Joined: 21 Jul 2006
Posts: 1550
Followers: 8

Kudos [?]: 191 [0], given: 1

GMAT Tests User
factor [#permalink] New post 09 Aug 2009, 11:10
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

80% (02:55) correct 20% (00:00) wrong based on 8 sessions
If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for which 3k is a factor of p?
A. 10
B. 12
C. 14
D. 16
E. 18


please show the fastest way to solve this.
thanks
Current Student
avatar
Affiliations: ?
Joined: 20 Jul 2009
Posts: 191
Location: Africa/Europe
Schools: Kellogg; Ross ($$); Tuck
Followers: 2

Kudos [?]: 27 [0], given: 6

Re: factor [#permalink] New post 09 Aug 2009, 13:02
I can see that any of these numbers is ok.
so I just pick 18.

P = 30! = 30x29x28x......x4x3x2x1

if 3K is a factor of p, it means that we can divide p by 3K and the result is an integer.
there is a "3" in the expression of p, and all numbers shown are also there.

the greatest one should then be OK.

is AO E??
Director
Director
User avatar
Joined: 01 Apr 2008
Posts: 909
Schools: IIM Lucknow (IPMX) - Class of 2014
Followers: 15

Kudos [?]: 203 [0], given: 18

GMAT Tests User
Re: factor [#permalink] New post 09 Aug 2009, 22:04
k should be the largest prime <=30. So k can be 29 !! as 3 * 29 is a factor of 30!.
However this option is not listed!!
Manager
Manager
avatar
Joined: 28 Jul 2009
Posts: 126
Location: India
Schools: NUS, NTU, SMU, AGSM, Melbourne School of Business
Followers: 6

Kudos [?]: 52 [0], given: 12

GMAT Tests User
Re: factor [#permalink] New post 09 Aug 2009, 22:22
Agree with Economist. But from the list, the best answer would be 18. Since all the prime factors of 18*3(2*3*3*3) would be in the product number. OA pls! :)
_________________

GMAT offended me. Now, its my turn!
Will do anything for Kudos! Please feel free to give one. :)

SVP
SVP
avatar
Joined: 21 Jul 2006
Posts: 1550
Followers: 8

Kudos [?]: 191 [0], given: 1

GMAT Tests User
Re: factor [#permalink] New post 10 Aug 2009, 13:45
No....OA is C

please explain :s
1 KUDOS received
Manager
Manager
avatar
Joined: 15 Jun 2009
Posts: 165
Followers: 1

Kudos [?]: 17 [1] , given: 8

GMAT Tests User
Re: factor [#permalink] New post 11 Aug 2009, 03:04
1
This post received
KUDOS
tarek99 wrote:
If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for which 3k is a factor of p?
A. 10
B. 12
C. 14
D. 16
E. 18


please show the fastest way to solve this.
thanks


Well ..I think question should read as 3^k ....i.e, If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for which 3^k is a factor of p?


Then C ..14 will be correct.. :?
1 KUDOS received
Manager
Manager
avatar
Joined: 25 Jul 2009
Posts: 117
Schools: NYU, NUS, ISB, DUKE, ROSS, DARDEN
Followers: 4

Kudos [?]: 141 [1] , given: 17

GMAT Tests User
Re: factor [#permalink] New post 11 Aug 2009, 03:32
1
This post received
KUDOS
age wrote:
tarek99 wrote:
If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for which 3k is a factor of p?
A. 10
B. 12
C. 14
D. 16
E. 18


please show the fastest way to solve this.
thanks


Well ..I think question should read as 3^k ....i.e, If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for which 3^k is a factor of p?


Then C ..14 will be correct.. :?


I agree. If C is the OA, then the questions should read as 3^k giving 14 as the answer.

Although if its not 3^k, then another interpretation of 3k could be 300 + k instead of 3*k, because 3*k makes the question silly. This means that when k=10, we get 310 and not 3*10 = 30

Thus proceeding with the "300 + k" assumption, we get:
P = 30!

Option A: 310
=> 310 = 2 * 5 * 31
=> 31 is a prime and is not present in 30!
Thus 310 is not a factor of P
=> A is Eliminated

Option B: 312
=> 312 = 2^3 * 3 * 13
Thus 312 is a factor of P
=> B is the correct answer !

Option C: 314
=> 314 = 2 * 157
=> 157 is a prime and is not present in 30!
Thus 314 is not a factor of P
=> C is Eliminated

Option D: 316
=> 316 = 2^2 * 79
=> 79 is a prime and is not present in 30!
Thus 316 is not a factor of P
=> D is Eliminated

Option E: 318
=> 310 = 2 * 3 * 53
=> 53 is a prime and is not present in 30!
Thus 318 is not a factor of P
=> E is Eliminated

ANS: B
_________________

KUDOS me if I deserve it !! :)

My GMAT Debrief - 740 (Q50, V39) | My Test-Taking Strategies for GMAT | Sameer's SC Notes

Senior Manager
Senior Manager
User avatar
Joined: 21 Jul 2009
Posts: 266
Location: New York, NY
Followers: 1

Kudos [?]: 35 [0], given: 23

GMAT Tests User
Re: factor [#permalink] New post 29 Aug 2009, 23:18
Factors of 31! include 14 times 3. Hence 3^14.
Number: Factors of 3
3 : 1
6 : 1
9 : 2
12 : 1
15 : 1
18 : 2
21 : 1
24 : 1
27 : 3
30 : 1
Total : 14

Last edited by mendelay on 30 Aug 2009, 14:29, edited 1 time in total.
1 KUDOS received
Manager
Manager
User avatar
Joined: 14 Aug 2009
Posts: 123
Followers: 2

Kudos [?]: 90 [1] , given: 13

Re: factor [#permalink] New post 30 Aug 2009, 05:52
1
This post received
KUDOS
if it is 3*k, answer is E, just 18 in, 30! is divisible by 3*18

if it is 3^k, answer is C, 30!has 3, 6, 9,....30 as the factors, includes 14 of 3.
_________________

Kudos me if my reply helps!

Re: factor   [#permalink] 30 Aug 2009, 05:52
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic factoring tt11234 3 15 Aug 2010, 12:53
2 Factors efet 2 15 Aug 2010, 05:29
Factoring Jinglander 1 12 Jul 2010, 17:53
2 Factoring hardaway7 8 18 Jan 2009, 12:20
Factor ldpedroso 1 11 May 2008, 14:34
Display posts from previous: Sort by

factor

  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®.