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

It is currently 22 Jul 2014, 06:11

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the average of eleven consecutive integers? 1) The

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 04 Apr 2007
Posts: 130
Followers: 1

Kudos [?]: 7 [0], given: 0

GMAT Tests User
What is the average of eleven consecutive integers? 1) The [#permalink] New post 13 Apr 2007, 21:11
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
What is the average of eleven consecutive integers?

1) The average of the first nine integers is 7.
2) The average of the last nine integers is 9

OA: D

I just setup the equation X/9 = 7, to get X = 63...but then after that I just started plugging in numbers that would add up to 63. Took a bit of time and just wondering if there is another method.
Director
Director
User avatar
Joined: 13 Dec 2006
Posts: 521
Location: Indonesia
Followers: 5

Kudos [?]: 90 [0], given: 0

GMAT Tests User
 [#permalink] New post 13 Apr 2007, 21:48
Hi, Answer is D

Explanation


lets say first number in the sequence is X then the sum of first 9consequitive number will be 9X+ 8 but its avg is 7 hence 9X + 8 = 63 so we can get the value of X and hence our answer. 1 is sufficient

Similarly 2 is also sufficient... hence answer is D

regards,

Amardeep
Manager
Manager
avatar
Joined: 25 Mar 2007
Posts: 82
Followers: 1

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

 [#permalink] New post 13 Apr 2007, 23:34
1. Average of first nine integers is 7
[ x+(x+1)+(x+2)+...+(x+8) ] / 9 = 7

this implies, (9x + 36)/9 = 7 => 9x+36=63 =>9x = 27 =>x=3

then the sequence is : 3,4,5,6,7,8,9,10,11,13,15 => 1. sufficient

2. Average of last nine integers is 9
same idea as above but start with x+2 2. sufficient

In either case, you can get the full sequence, therefore, D.
Director
Director
User avatar
Joined: 14 Jan 2007
Posts: 783
Followers: 2

Kudos [?]: 43 [0], given: 0

GMAT Tests User
 [#permalink] New post 14 Apr 2007, 03:27
Use this formula rather than adding up the consecutive integers:

lets consider the numbers are x, x+1, x+2.....

average of first 7 CONSECUTIVE integers = (First term+last term)/2 = (x +x+6)/2 = 7
solve for x
now the average of 11 integers can be found out. SUFF

Statement2:
The same way, the average of the last 9 CONSECUTIVE integers = [(x+2)+(x+10)]/2 =9
solve for x , average of 11 integers can be found out. SUFF

Hence it's 'D'
  [#permalink] 14 Apr 2007, 03:27
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic What is the average of eleven consecutive integers? 1. The ritula 2 25 May 2008, 07:49
What is the average (arithmetic mean) of eleven consecutive Hang Tuah 3 23 Dec 2007, 23:16
what is the AVG of eleven consecutive integers? 1. AVG of el1981 3 28 Oct 2007, 17:58
What is the average of eleven consecutive integers? 1) lhotseface 13 26 Mar 2006, 21:44
What is the average of eleven consecutive integers? 1) MBAHopeful 5 25 Dec 2005, 19:24
Display posts from previous: Sort by

What is the average of eleven consecutive integers? 1) The

  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®.