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

It is currently 01 Sep 2015, 14:43
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

For which of the following values of x is the equation

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 03 Apr 2006
Posts: 46
Followers: 0

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

For which of the following values of x is the equation [#permalink] New post 09 Jun 2007, 15:15
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

For which of the following values of x is the equation (x+4)!/x!= (x + 1)! true?

6

7

8

9

10
Director
Director
User avatar
Joined: 13 Mar 2007
Posts: 545
Schools: MIT Sloan
Followers: 4

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

 [#permalink] New post 09 Jun 2007, 16:03
(A)

did nothing great - just substitued the value and it worked !

is there any other way?
CEO
CEO
User avatar
Joined: 17 May 2007
Posts: 2994
Followers: 59

Kudos [?]: 493 [0], given: 210

 [#permalink] New post 09 Jun 2007, 18:19
You can simplify a little bit.

(x+4)! / x! can be written as (x+4)(x+3)(x+2)(x+1) --> LHS
(x+1)! = (x+1)(x)(x-1).... (1) --> RHS and u can cancel out (x+1)
so now the equation looks like :
(x+4)(x+3)(x+2) = x!

Pluggin in values is slightly easier now. Answer is still 6

which is A
  [#permalink] 09 Jun 2007, 18:19
Display posts from previous: Sort by

For which of the following values of x is the equation

  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®.