The sequence x1, x2, x3,..., is such that Xn = 1/n - 1/(n+1) : GMAT Problem Solving (PS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 19 Jan 2017, 09:57

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# The sequence x1, x2, x3,..., is such that Xn = 1/n - 1/(n+1)

Author Message
TAGS:

### Hide Tags

Intern
Joined: 04 Sep 2009
Posts: 43
Followers: 1

Kudos [?]: 54 [0], given: 9

The sequence x1, x2, x3,..., is such that Xn = 1/n - 1/(n+1) [#permalink]

### Show Tags

22 Sep 2012, 09:19
1
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

61% (02:23) correct 39% (02:05) wrong based on 120 sessions

### HideShow timer Statistics

The sequence x1, x2, x3,..., is such that Xn = 1/n - (1/(n+1)). What is the sum of the first 100 terms of the sequence?

A. 201/100
B. 99/100
C. 100/101
D. 1/10000
E. 0
[Reveal] Spoiler: OA

_________________

Aeros
"Why are you trying so hard to fit in when you were born to stand out?"
"Do or do not. There is no 'try'..."

Last edited by Bunuel on 22 Sep 2012, 09:31, edited 1 time in total.
Renamed the topic and edited the question.
Intern
Joined: 02 Nov 2009
Posts: 44
Location: India
Concentration: General Management, Technology
GMAT Date: 04-21-2013
GPA: 4
WE: Information Technology (Internet and New Media)
Followers: 3

Kudos [?]: 50 [0], given: 8

Re: The sequence x1, x2, x3,..., is such that Xn = 1/n - 1/(n+1) [#permalink]

### Show Tags

22 Sep 2012, 10:18
Given Xn = 1/n - (1/(n+1))
--> X1=1-(1/2)
X2=(1/2)-(1/3)
X3=(1/3)-(1/4)

x1+x2+x3 = 1-(1/4) as other terms gets cancelled out...

following the same approach x1+x2...+x100 =1-(1/101) =100/101
_________________

KPV

Manager
Joined: 18 Oct 2013
Posts: 81
Location: India
Concentration: Technology, Finance
GMAT 1: 580 Q48 V21
GMAT 2: 530 Q49 V13
GMAT 3: 590 Q49 V21
WE: Information Technology (Computer Software)
Followers: 3

Kudos [?]: 28 [0], given: 36

Re: The sequence x1, x2, x3,..., is such that Xn = 1/n - 1/(n+1) [#permalink]

### Show Tags

20 Nov 2013, 10:50

X1=1-1/2
x2=1/2-1/3
x3=1/3-1/4
.....
x99=1/99-1/100
x100=1/100-1/101

sum=X1+X2+X3+....X100=1-1/2+1/2-1/3+.......1/99-1/100+1/100-1/101=1-1/101=100/101

.
.
Re: The sequence x1, x2, x3,..., is such that Xn = 1/n - 1/(n+1)   [#permalink] 20 Nov 2013, 10:50
Similar topics Replies Last post
Similar
Topics:
10 In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk 10 14 Dec 2010, 16:40
6 If the sequence x1, x2, x3, ..., xn, given that x1 = 3 and x 4 18 Sep 2010, 09:41
13 If the sequence x1, x2, x3, ... xn, ... is such that x1 = 3 4 04 Aug 2010, 03:17
21 If the sequence x_1, x_2, x_3, …, x_n, ... is such that x_1 9 15 Oct 2009, 16:58
24 If the sequence x1, x2, x3, …, xn, … is such that x1 = 3 13 16 Sep 2009, 23:05
Display posts from previous: Sort by