GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 26 Feb 2020, 10:55 ### 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

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.  # Consider the set S = {2, 3, 4, ...., 2n+1), where n is a positive inte

Author Message
TAGS:

### Hide Tags

Math Expert V
Joined: 02 Sep 2009
Posts: 61510
Consider the set S = {2, 3, 4, ...., 2n+1), where n is a positive inte  [#permalink]

### Show Tags 00:00

Difficulty:

(N/A)

Question Stats: 62% (02:45) correct 38% (02:40) wrong based on 13 sessions

### HideShow timer Statistics

Consider the set S = {2, 3, 4, ...., 2n+1), where n is a positive integer larger than 2007. Define X as the average of the odd integers in S and Y as the average of the even integers in S. What is the value of X – Y?

(A) 0
(B) 1
(C) 2008
(D) n/2
(E) (n + 1)/(2n)

_________________
Intern  B
Joined: 30 Dec 2019
Posts: 6
Re: Consider the set S = {2, 3, 4, ...., 2n+1), where n is a positive inte  [#permalink]

### Show Tags

Take smaller values of n, such as n=5 or n=6.

Notice that n=5 => X=7,Y=6
n=6 => X=8, Y=7.

As we can see, X=n+2 and Y=n+1.

Hence, X-Y = 1.

Option B
Director  P
Joined: 16 Jan 2019
Posts: 575
Location: India
Concentration: General Management
WE: Sales (Other)
Re: Consider the set S = {2, 3, 4, ...., 2n+1), where n is a positive inte  [#permalink]

### Show Tags

1
Even set = {2,4,6,8,...2n}
Odd set = {3,5,7,9,...2n+1}

By property, if a certain number x is added to all elements of a set, the average of the set increases by x

By this property, since the odd set is just the even set with 1 added to all elements, the average of the odd set must be 1 greater than the average of the even set

So X-Y=1

Posted from my mobile device Re: Consider the set S = {2, 3, 4, ...., 2n+1), where n is a positive inte   [#permalink] 01 Jan 2020, 05:41
Display posts from previous: Sort by

# Consider the set S = {2, 3, 4, ...., 2n+1), where n is a positive inte  