It is currently 14 Dec 2017, 05:28

# Decision(s) Day!:

CHAT Rooms | Wharton R1 | Stanford R1 | Tuck R1 | Ross R1 | Haas R1

### 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 proceeding list of terms is an arithmetic sequence. How many terms

Author Message
TAGS:

### Hide Tags

Intern
Joined: 23 Mar 2017
Posts: 2

Kudos [?]: 2 [0], given: 1

The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

01 Apr 2017, 06:12
2
This post was
BOOKMARKED
00:00

Difficulty:

55% (hard)

Question Stats:

57% (00:52) correct 43% (00:56) wrong based on 122 sessions

### HideShow timer Statistics

The proceeding list of terms is an arithmetic sequence. How many terms are included in the list?

2, $$a_2$$, ..., 247

(1) $$a_n=5n-3$$
(2) $$a_2=7$$
[Reveal] Spoiler: OA

Kudos [?]: 2 [0], given: 1

Moderator
Joined: 21 Jun 2014
Posts: 956

Kudos [?]: 490 [1], given: 113

Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
Re: The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

01 Apr 2017, 21:05
1
KUDOS
samuelz wrote:
The proceeding list of terms is an arithmetic sequence. How many terms are included in the list?
2,$$a_2$$,...,247

1)$$a_n$$=5n-3
2)$$a_2$$=7

2, a2, ......,247

stmt-1:
an = 5n - 3
a2 = 5*2 - 3 = 7

notice that the given sequence is arithmatic. it means the difference between the terms will be same i.e. a2 - a1 = 7-2 = 5. Knowing this difference and as first and last term is given you can find the number of terms in sequence.
Sufficient

stmt-2:
same as stmt-1. you get to know the value of a2 and hence the difference between terms.
sufficient.

What is the source of this question?
_________________

---------------------------------------------------------------
Target - 720-740
http://gmatclub.com/forum/information-on-new-gmat-esr-report-beta-221111.html
http://gmatclub.com/forum/list-of-one-year-full-time-mba-programs-222103.html

Kudos [?]: 490 [1], given: 113

Intern
Joined: 23 Mar 2017
Posts: 2

Kudos [?]: 2 [0], given: 1

Re: The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

02 Apr 2017, 07:11
Thanks a lot for the explanation. I've found this question in McGraw-Hill Gmat Prep books.

Kudos [?]: 2 [0], given: 1

Intern
Joined: 14 Jan 2017
Posts: 6

Kudos [?]: [0], given: 48

GMAT 1: 460 Q27 V27
GPA: 3.3
WE: Operations (Manufacturing)
Re: The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

03 Apr 2017, 14:50
Hello,
FOR
(1) I tried 247=5n-3, which got me n=244/5, How should I interpret this result?
What am I doing wrong?

Thanks,

Miral

Kudos [?]: [0], given: 48

Math Expert
Joined: 02 Sep 2009
Posts: 42606

Kudos [?]: 135613 [1], given: 12705

Re: The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

03 Apr 2017, 23:14
1
KUDOS
Expert's post
mbhatt wrote:
Hello,
FOR
(1) I tried 247=5n-3, which got me n=244/5, How should I interpret this result?
What am I doing wrong?

Thanks,

Miral

247 = 5n - 3

250 = 5n

n = 250/5 = 50.
_________________

Kudos [?]: 135613 [1], given: 12705

Senior Manager
Joined: 02 Apr 2014
Posts: 263

Kudos [?]: 18 [0], given: 499

Re: The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

01 Nov 2017, 11:15
Hi Bunuel,
I have one question, does arithmetic sequence necessarily mean arithmetic progression?

Statement 1: sufficient and substituting the value for n, we find the sequence is actually arithmetic progression.

Statement 2: can there be any sequence whose equation, gives 2, 7,.....247, ? may be or may be not, accordingly number of terms in the list will vary.

So confused between A and D

Kudos [?]: 18 [0], given: 499

Moderator
Joined: 21 Jun 2014
Posts: 956

Kudos [?]: 490 [0], given: 113

Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
Re: The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

01 Nov 2017, 12:13
hellosanthosh2k2 wrote:
Hi Bunuel,
I have one question, does arithmetic sequence necessarily mean arithmetic progression?

Statement 1: sufficient and substituting the value for n, we find the sequence is actually arithmetic progression.

Statement 2: can there be any sequence whose equation, gives 2, 7,.....247, ? may be or may be not, accordingly number of terms in the list will vary.

So confused between A and D

there can be less or more terms in the sequence 2, 7,... 247 BUT because the question stamp states that "The proceeding list of terms is an arithmetic sequence", the number of terms are fixed!

and yes - arithmatic sequence means arithmatic progression.
_________________

---------------------------------------------------------------
Target - 720-740
http://gmatclub.com/forum/information-on-new-gmat-esr-report-beta-221111.html
http://gmatclub.com/forum/list-of-one-year-full-time-mba-programs-222103.html

Kudos [?]: 490 [0], given: 113

Intern
Joined: 12 Oct 2017
Posts: 37

Kudos [?]: 21 [1], given: 13

Re: The proceeding list of terms is an arithmetic sequence. How many terms [#permalink]

### Show Tags

01 Nov 2017, 18:51
1
KUDOS
Because we already know that "the proceeding list of terms is an arithmetic sequence" and that the value of the first and the last term, we can calculate the number of terms in the list when we know the difference between 2 consecutive terms.

(1) a(n)=5n−3 => a2 = 10 - 3 =7 => a2 - a1 = 5 => sufficient.

(2) a2=7 => same as (1)

Kudos [?]: 21 [1], given: 13

Re: The proceeding list of terms is an arithmetic sequence. How many terms   [#permalink] 01 Nov 2017, 18:51
Display posts from previous: Sort by