It is currently 19 Nov 2017, 11:09

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The sum of 4th and 13th term of an AP is 35. What is the sum

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
avatar
Joined: 17 Sep 2011
Posts: 191

Kudos [?]: 140 [0], given: 8

The sum of 4th and 13th term of an AP is 35. What is the sum [#permalink]

Show Tags

New post 31 Jan 2012, 17:53
The sum of 4th and 13th term of an AP is 35. What is the sum of the first 15 terms of the AP ?

Could someone please provide a solution to this problem ?
_________________

_________________
Giving +1 kudos is a better way of saying 'Thank You'.

Kudos [?]: 140 [0], given: 8

VP
VP
User avatar
S
Status: Top MBA Admissions Consultant
Joined: 24 Jul 2011
Posts: 1354

Kudos [?]: 651 [0], given: 20

GMAT 1: 780 Q51 V48
GRE 1: 1540 Q800 V740
Re: The sum of 4th and 13th term of an AP is 35. What is the sum [#permalink]

Show Tags

New post 31 Jan 2012, 19:59
We can find the answer for the sum of the first 16 terms of the AP.

The 4th term of an AP = a + 3d [a= first term and d=common difference]
The 13th term of the AP = a + 12d
=> 2a + 15d = 35

Sum of the first 16 terms of the AP = (16/2) [2a + 15d]
= 8 * 35
= 280
_________________

GyanOne | Top MBA Rankings and MBA Admissions Blog

Top MBA Admissions Consulting | Top MiM Admissions Consulting

Premium MBA Essay Review|Best MBA Interview Preparation|Exclusive GMAT coaching

Get a FREE Detailed MBA Profile Evaluation | Call us now +91 98998 31738


Last edited by GyanOne on 03 Feb 2012, 00:55, edited 1 time in total.

Kudos [?]: 651 [0], given: 20

Manager
Manager
avatar
Joined: 17 Sep 2011
Posts: 191

Kudos [?]: 140 [0], given: 8

Re: The sum of 4th and 13th term of an AP is 35. What is the sum [#permalink]

Show Tags

New post 01 Feb 2012, 01:03
Thanks for the solution
_________________

_________________
Giving +1 kudos is a better way of saying 'Thank You'.

Kudos [?]: 140 [0], given: 8

Intern
Intern
avatar
Joined: 31 Jul 2011
Posts: 13

Kudos [?]: 4 [0], given: 7

Re: The sum of 4th and 13th term of an AP is 35. What is the sum [#permalink]

Show Tags

New post 02 Feb 2012, 10:29
Hi GyanOne,
Is not the sum of the first n terms of an AP series given by :

S(n) = (n/2) [2a + (n-1)d]

so S(15) = (15/2) [2a +14d] ?

Kudos [?]: 4 [0], given: 7

VP
VP
User avatar
S
Status: Top MBA Admissions Consultant
Joined: 24 Jul 2011
Posts: 1354

Kudos [?]: 651 [0], given: 20

GMAT 1: 780 Q51 V48
GRE 1: 1540 Q800 V740
Re: The sum of 4th and 13th term of an AP is 35. What is the sum [#permalink]

Show Tags

New post 03 Feb 2012, 00:56
radhagovindaradjou,

We can't sum for 15 terms here, but can for 16. The expression you have put down is correct, except we will not be able to find a numerical value for the expression. We can sum to 16 terms though, and that is what I have done.
_________________

GyanOne | Top MBA Rankings and MBA Admissions Blog

Top MBA Admissions Consulting | Top MiM Admissions Consulting

Premium MBA Essay Review|Best MBA Interview Preparation|Exclusive GMAT coaching

Get a FREE Detailed MBA Profile Evaluation | Call us now +91 98998 31738

Kudos [?]: 651 [0], given: 20

Re: The sum of 4th and 13th term of an AP is 35. What is the sum   [#permalink] 03 Feb 2012, 00:56
Display posts from previous: Sort by

The sum of 4th and 13th term of an AP is 35. What is the sum

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.