It is currently 16 Dec 2017, 05:11

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the value of the integer n? (1) N!= (N-1)!*N (2)

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 16 May 2011
Posts: 203

Kudos [?]: 101 [0], given: 37

Concentration: Finance, Real Estate
GMAT Date: 12-27-2011
WE: Law (Law)
GMAT ToolKit User
What is the value of the integer n? (1) N!= (N-1)!*N (2) [#permalink]

Show Tags

New post 06 Jun 2011, 09:39
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

82% (01:02) correct 18% (01:38) wrong based on 72 sessions

HideShow timer Statistics

What is the value of the integer n?

(1) N!= (N-1)!*N

(2) N^3+3N^2+2N is divisible by 3

OPEN DISCUSSION OF THIS QUESTION IS HERE: https://gmatclub.com/forum/what-is-the- ... 26638.html
[Reveal] Spoiler: OA

Kudos [?]: 101 [0], given: 37

1 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 24 Mar 2011
Posts: 428

Kudos [?]: 223 [1], given: 20

Location: Texas
Re: What is the value of the integer n? (1) N!= (N-1)!*N (2) [#permalink]

Show Tags

New post 06 Jun 2011, 11:36
1
This post received
KUDOS
St 1 doesnt provide any information. Its just another way of expressing N!.

St 2 - solving the equation we get N (N+1) (N+2) is divisible by 3. N can have lot of values like 4,5,6,7.. etc.
so not sufficient.

together also we dont get a unique value of N.

So E.

I am not sure if this is GMAT Q. Does Gmat provide a sufficiency statement like 1? What is the source of the Q.

Kudos [?]: 223 [1], given: 20

Manager
Manager
avatar
Joined: 16 May 2011
Posts: 203

Kudos [?]: 101 [0], given: 37

Concentration: Finance, Real Estate
GMAT Date: 12-27-2011
WE: Law (Law)
GMAT ToolKit User
Re: What is the value of the integer n? (1) N!= (N-1)!*N (2) [#permalink]

Show Tags

New post 06 Jun 2011, 13:24
it's taken from manhattan archive- which includes some of the hardest i have seen and frankly i believe that only som GC legends will be able to solve some of them under 4 minutes.

by the way, how do you decide to prefer E (which is correct) and not C

Kudos [?]: 101 [0], given: 37

Intern
Intern
avatar
Joined: 28 Mar 2011
Posts: 22

Kudos [?]: 5 [0], given: 2

GMAT 1: 720 Q50 V39
Re: What is the value of the integer n? (1) N!= (N-1)!*N (2) [#permalink]

Show Tags

New post 06 Jun 2011, 13:39
1/ N! = N(N-1)(N-2).... = N[(N-1)(N-2)....] = N*(N-1)! so there is no new info brought by this by 1/. It is just another expression of N!

2/ N^3+3N^2+2N is divisible by 3: You can find endless integers fulfilling this condition.

--> The answer is E

Kudos [?]: 5 [0], given: 2

1 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 24 Mar 2011
Posts: 428

Kudos [?]: 223 [1], given: 20

Location: Texas
Re: What is the value of the integer n? (1) N!= (N-1)!*N (2) [#permalink]

Show Tags

New post 06 Jun 2011, 13:59
1
This post received
KUDOS
dimri10 wrote:
it's taken from manhattan archive- which includes some of the hardest i have seen and frankly i believe that only som GC legends will be able to solve some of them under 4 minutes.

by the way, how do you decide to prefer E (which is correct) and not C


Vow, MGMAT? i guess than must be to trick people.

Basically, if you combine A and B, there is no additional info other than what we have achieved in B. Because remember that A doesn't provide any other info other than its just different way of expressng N!.

Kudos [?]: 223 [1], given: 20

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42630

Kudos [?]: 135805 [0], given: 12714

Re: What is the value of the integer n? (1) N!= (N-1)!*N (2) [#permalink]

Show Tags

New post 03 Dec 2017, 01:17
What is the value of the integer n?

(1) n!=n*(n – 1)! --> n*(n – 1)! equals to n! itself, so we have n!=n!. Useless statement.

(2) n^3 + 3n^2 + 2n is divisible by 3 --> n(n^2+3n+2)=n(n+1)(n+2): we have the product of 3 consecutive integers, which is ALWAYS divisible by 3. Useless statement.

(1)+(2) Two useless statements. Not sufficient.

Answer: E.

OPEN DISCUSSION OF THIS QUESTION IS HERE: https://gmatclub.com/forum/what-is-the- ... 26638.html
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135805 [0], given: 12714

Re: What is the value of the integer n? (1) N!= (N-1)!*N (2)   [#permalink] 03 Dec 2017, 01:17
Display posts from previous: Sort by

What is the value of the integer n? (1) N!= (N-1)!*N (2)

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.