In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk : GMAT Problem Solving (PS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 21 Jan 2017, 08:11

### 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

# In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 36590
Followers: 7090

Kudos [?]: 93325 [0], given: 10557

In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

05 Mar 2014, 01:20
Expert's post
21
This post was
BOOKMARKED
00:00

Difficulty:

55% (hard)

Question Stats:

65% (02:44) correct 35% (03:03) wrong based on 531 sessions

### HideShow timer Statistics

The Official Guide For GMAT® Quantitative Review, 2ND Edition

In the sequence $$x_0, \ x_1, \ x_2, \ ... \ x_n$$, each term from $$x_1$$ to $$x_k$$ is 3 greater than the previous term, and each term from $$x_{k+1}$$ to $$x_n$$ is 3 less than the previous term, where $$n$$ and $$k$$ are positive integers and $$k<n$$. If $$x_0=x_n=0$$ and if $$x_k=15$$, what is the value of $$n$$?

(A) 5
(B) 6
(C) 9
(D) 10
(E) 15

Problem Solving
Question: 131
Category: Algebra Sequences
Page: 78
Difficulty: 600

GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition - Quantitative Questions Project

Each week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution.

We'll be glad if you participate in development of this project:
2. Please vote for the best solutions by pressing Kudos button;
3. Please vote for the questions themselves by pressing Kudos button;
4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Thank you!
[Reveal] Spoiler: OA

_________________
Math Expert
Joined: 02 Sep 2009
Posts: 36590
Followers: 7090

Kudos [?]: 93325 [2] , given: 10557

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

05 Mar 2014, 01:20
2
KUDOS
Expert's post
2
This post was
BOOKMARKED
SOLUTION

In the sequence $$x_0, \ x_1, \ x_2, \ ... \ x_n$$, each term from $$x_1$$ to $$x_k$$ is 3 greater than the previous term, and each term from $$x_{k+1}$$ to $$x_n$$ is 3 less than the previous term, where $$n$$ and $$k$$ are positive integers and $$k<n$$. If $$x_0=x_n=0$$ and if $$x_k=15$$, what is the value of $$n$$?

(A) 5
(B) 6
(C) 9
(D) 10
(E) 15

Probably the easiest way will be to write down all the terms in the sequence from $$x_0=0$$ to $$x_n=0$$. Note that each term from from $$x_0=0$$ to $$x_k=15$$ is 3 greater than the previous and each term from $$x_{k+1}$$ to $$x_n$$ is 3 less than the previous term:

So we'll have: $$x_0=0$$, 3, 6, 9, 12, $$x_k=15$$, 12, 9, 6, 3, $$x_n=0$$. So we have 11 terms from $$x_0$$ to $$x_n$$ thus $$n=10$$.

_________________
SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1858
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Followers: 47

Kudos [?]: 1935 [0], given: 193

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

05 Mar 2014, 19:25
1
This post was
BOOKMARKED

Series will be formed as below starting from x0 = 0 & ending up with x10 = 0

xk = 15

0, 3, 6, 9, 12, 15, 12, 9, 6, 3, 0
_________________

Kindly press "+1 Kudos" to appreciate

Math Expert
Joined: 02 Sep 2009
Posts: 36590
Followers: 7090

Kudos [?]: 93325 [0], given: 10557

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

08 Mar 2014, 11:40
Expert's post
1
This post was
BOOKMARKED
SOLUTION

In the sequence $$x_0, \ x_1, \ x_2, \ ... \ x_n$$, each term from $$x_1$$ to $$x_k$$ is 3 greater than the previous term, and each term from $$x_{k+1}$$ to $$x_n$$ is 3 less than the previous term, where $$n$$ and $$k$$ are positive integers and $$k<n$$. If $$x_0=x_n=0$$ and if $$x_k=15$$, what is the value of $$n$$?

(A) 5
(B) 6
(C) 9
(D) 10
(E) 15

Probably the easiest way will be to write down all the terms in the sequence from $$x_0=0$$ to $$x_n=0$$. Note that each term from from $$x_0=0$$ to $$x_k=15$$ is 3 greater than the previous and each term from $$x_{k+1}$$ to $$x_n$$ is 3 less than the previous term:

So we'll have: $$x_0=0$$, 3, 6, 9, 12, $$x_k=15$$, 12, 9, 6, 3, $$x_n=0$$. So we have 11 terms from $$x_0$$ to $$x_n$$ thus $$n=10$$.

_________________
Manager
Joined: 28 May 2014
Posts: 64
Schools: NTU '16
GMAT 1: 620 Q49 V27
Followers: 0

Kudos [?]: 1 [0], given: 31

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

26 Jul 2014, 21:17
Bunuel,

If the total terms ins sequence are 11, how is the no of terms n 10? Can you please explain? Thanks in advance.
Math Expert
Joined: 02 Sep 2009
Posts: 36590
Followers: 7090

Kudos [?]: 93325 [1] , given: 10557

In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

27 Jul 2014, 02:25
1
KUDOS
Expert's post
sri30kanth wrote:
Bunuel,

If the total terms ins sequence are 11, how is the no of terms n 10? Can you please explain? Thanks in advance.

Yes, the number of terms is 11 but we start from $$x_0$$, not from $$x_1$$, hence n=10.
_________________
Manager
Joined: 28 May 2014
Posts: 64
Schools: NTU '16
GMAT 1: 620 Q49 V27
Followers: 0

Kudos [?]: 1 [0], given: 31

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

27 Jul 2014, 05:53
Yes so the correct ans should be 11 which is not present in any of the options.
Math Expert
Joined: 02 Sep 2009
Posts: 36590
Followers: 7090

Kudos [?]: 93325 [1] , given: 10557

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

27 Jul 2014, 08:28
1
KUDOS
Expert's post
sri30kanth wrote:
Yes so the correct ans should be 11 which is not present in any of the options.

Еhe number of terms is 11 but we start from $$x_0$$, not from $$x_1$$, hence n=10.
_________________
Manager
Joined: 28 May 2014
Posts: 64
Schools: NTU '16
GMAT 1: 620 Q49 V27
Followers: 0

Kudos [?]: 1 [1] , given: 31

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

28 Jul 2014, 08:27
1
KUDOS
Got it now. Thanks a lot Bunuel.
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13480
Followers: 576

Kudos [?]: 163 [0], given: 0

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

28 Sep 2015, 16:34
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13480
Followers: 576

Kudos [?]: 163 [0], given: 0

Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk [#permalink]

### Show Tags

13 Nov 2016, 16:07
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk   [#permalink] 13 Nov 2016, 16:07
Similar topics Replies Last post
Similar
Topics:
37 In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk 21 26 Jan 2012, 03:15
10 In the Sequence x0, x1, x2, ..., xn, each term from x1 to xk 10 14 Dec 2010, 16:40
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