GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 23 Jan 2019, 12:27

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 in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
  • Key Strategies to Master GMAT SC

     January 26, 2019

     January 26, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.
  • Free GMAT Number Properties Webinar

     January 27, 2019

     January 27, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.

What is the average of the first 15 positive integers?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52431
What is the average of the first 15 positive integers?  [#permalink]

Show Tags

New post 28 Feb 2018, 23:40
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

85% (00:32) correct 15% (00:25) wrong based on 36 sessions

HideShow timer Statistics

Senior PS Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3334
Location: India
GPA: 3.12
Premium Member CAT Tests
What is the average of the first 15 positive integers?  [#permalink]

Show Tags

New post 01 Mar 2018, 00:04
Bunuel wrote:
What is the average of the first 15 positive integers?

(A) 7

(B) 7.5

(C) 8

(D) 8.5

(E) 9


Here, we are talking about an AP with an odd number of elements.
In such a set,
1. the middle term is the average of the AP.
2. the average is the average of first and last elements in the AP.

Since it is a small set, we can write it down to clarity: 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

Average is 8(the middle term) or \(\frac{1+15}{2} = \frac{16}{2} = 8\)

Therefore, the average of the first 15 positive integers is 8(Option C)
_________________

You've got what it takes, but it will take everything you've got

VP
VP
User avatar
P
Joined: 31 Oct 2013
Posts: 1014
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
Re: What is the average of the first 15 positive integers?  [#permalink]

Show Tags

New post 01 Mar 2018, 01:50
Bunuel wrote:
What is the average of the first 15 positive integers?

(A) 7

(B) 7.5

(C) 8

(D) 8.5

(E) 9


this question can be solved in several ways. we have to find the sum of all the positive integers
which can be done by using this formula:

n(n+1)/2
=15*16/2
=120
average =120/15
=8
option c is the correct one.
Target Test Prep Representative
User avatar
P
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 4612
Location: United States (CA)
Re: What is the average of the first 15 positive integers?  [#permalink]

Show Tags

New post 02 Mar 2018, 09:39
Bunuel wrote:
What is the average of the first 15 positive integers?

(A) 7

(B) 7.5

(C) 8

(D) 8.5

(E) 9


Since we have a set of consecutive integers, we can determine the average using the following equation:

average = (1st integer + last integer)/2

average = (1 + 15)/2 = 16/2 = 8

Answer: C
_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Manager
Manager
avatar
S
Joined: 23 Sep 2016
Posts: 214
Premium Member Reviews Badge
What is the average of the first 15 positive integers?  [#permalink]

Show Tags

New post 03 Mar 2018, 02:36
Bunuel wrote:
What is the average of the first 15 positive integers?

(A) 7

(B) 7.5

(C) 8

(D) 8.5

(E) 9

IMO C
sum of 1st 15 positive integer
=n*(a+l)/2 (n=no. of terms, a= first term , and l is last term)
=15(1+15)/2
=15*8
average = 15*8/15=8
GMAT Club Bot
What is the average of the first 15 positive integers? &nbs [#permalink] 03 Mar 2018, 02:36
Display posts from previous: Sort by

What is the average of the first 15 positive integers?

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.