Find all School-related info fast with the new School-Specific MBA Forum

It is currently 31 Jul 2015, 02:15
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If m equals the sum of the even integers from 2 to 16

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
avatar
Status: Finally Done. Admitted in Kellogg for 2015 intake
Joined: 25 Jun 2011
Posts: 552
Location: United Kingdom
Concentration: International Business, Strategy
GMAT 1: 730 Q49 V40
GPA: 2.9
WE: Information Technology (Consulting)
Followers: 32

Kudos [?]: 1249 [0], given: 217

If m equals the sum of the even integers from 2 to 16 [#permalink] New post 01 Mar 2012, 14:07
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

78% (02:19) correct 22% (00:57) wrong based on 90 sessions
If m equals the sum of the even integers from 2 to 16, inclusive, and n equals the sum of the odd integers from 1 to 15, inclusive, what is the value of m - n ?

(A) 1
(B) 7
(C) 8
(D) 15
(E) 16

Any idea how can the answer be
[Reveal] Spoiler:
C?
[Reveal] Spoiler: OA

_________________

Best Regards,
E.

MGMAT 1 --> 530
MGMAT 2--> 640
MGMAT 3 ---> 610
GMAT ==> 730

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28781
Followers: 4592

Kudos [?]: 47371 [0], given: 7123

Re: If m equals the sum of the even integers from 2 to 16 [#permalink] New post 01 Mar 2012, 14:27
Expert's post
1
This post was
BOOKMARKED
enigma123 wrote:
If m equals the sum of the even integers from 2 to 16, inclusive, and n equals the sum of the odd integers from 1 to 15, inclusive, what is the value of m - n ?
(A) 1
(B) 7
(C) 8
(D) 15
(E) 16

Any idea how can the answer be
[Reveal] Spoiler:
C
?


Even integer from 2 to 16, inclusive (2, 4, 6, ..., 16) as well as odd integers from 1 to 15, inclusive (1, 3, 5, ..., 15) represent evenly spaced set (aka arithmetic progression). Now, the sum of the elements in any evenly spaced set is the mean (average) multiplied by the number of terms, where the mean of the set is (first+last)/2. (Check Number Theory chapter of Math Book for more: math-number-theory-88376.html)

There are 8 even integers from 2 to 16, inclusive, their sum equals to (first+last)/2*(number of terms)=(2+16)/2*8=72;

There are 8 odd integers from 1 to 15, inclusive, their sum equals to (first+last)/2*(number of terms)=(1+15)/2*8=64;

Difference: 72-64=8,

Answer: C.

Or: 2+4+6+8+10+12+14+16-(1+3+5+7+9+11+13+15)= (2-1)+(4-3)+(6-5)+(8-7)+(10-9)+(12-11)+(14-13)+(16-15)=1+1+1+1+1+1+1+1=8.

Answer: C.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. Tricky questions from previous years.

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5697
Followers: 322

Kudos [?]: 62 [0], given: 0

Premium Member
Re: If m equals the sum of the even integers from 2 to 16 [#permalink] New post 24 Oct 2014, 02:06
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 Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1859
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Followers: 23

Kudos [?]: 1010 [0], given: 193

Re: If m equals the sum of the even integers from 2 to 16 [#permalink] New post 27 Oct 2014, 20:58
enigma123 wrote:
If m equals the sum of the even integers from 2 to 16, inclusive, and n equals the sum of the odd integers from 1 to 15, inclusive, what is the value of m - n ?

(A) 1
(B) 7
(C) 8
(D) 15
(E) 16

Any idea how can the answer be
[Reveal] Spoiler:
C?


2 * 1 = 2

2 * 8 = 16

There are 8 even integers from 2 to 16

For every even integer, there is a 1 less odd integer whose subtraction will give result 1

(16-15) + (14-13) ................. (2 - 1)

This is repeated 8 times = 8 * 1 = 8

Answer = C
_________________

Kindly press "+1 Kudos" to appreciate :)

Re: If m equals the sum of the even integers from 2 to 16   [#permalink] 27 Oct 2014, 20:58
    Similar topics Author Replies Last post
Similar
Topics:
5 Experts publish their posts in the topic If a equals the sum of the even integers from 2 to 200, inclusive, and Drik 6 06 Jan 2013, 00:24
4 Experts publish their posts in the topic If x is equal to the sum of the integers from 30 to 50 nimc2012 7 08 Feb 2012, 14:31
19 If integer k is equal to the sum of all even multiples of 15 GK_Gmat 30 01 Jul 2007, 23:08
9 Experts publish their posts in the topic If x is equal to the sum of the even integers from 40 to 60 tejal777 18 03 Jul 2009, 19:07
5 Integer x is equal to the product of all even numbers from 2 to 60, in tejal777 8 13 Sep 2009, 20:56
Display posts from previous: Sort by

If m equals the sum of the even integers from 2 to 16

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.