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

It is currently 15 Oct 2019, 19:21

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

If x is a sum of all even integers on the interval 13...65

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

Hide Tags

Find Similar Topics 
Intern
Intern
avatar
Joined: 26 Sep 2012
Posts: 23
If x is a sum of all even integers on the interval 13...65  [#permalink]

Show Tags

New post 29 Jun 2014, 08:26
1
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

62% (02:02) correct 38% (02:27) wrong based on 74 sessions

HideShow timer Statistics

If x is a sum of all even integers on the interval 13...65 and y is their number, what is the GCD (x, y)?

(A) 1
(B) 13
(C) 26
(D) 52
(E) 1014
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58340
If x is a sum of all even integers on the interval 13...65  [#permalink]

Show Tags

New post 29 Jun 2014, 09:12
Maksym wrote:
If x is a sum of all even integers on the interval 13...65 and y is their number, what is the GCD (x, y)?

(A) 1
(B) 13
(C) 26
(D) 52
(E) 1014


y is the number of even integers from 14 to 64, inclusive = (largest - smallest)/2 + 1 = (64 - 14)/2 + 1 = 26. (Check this: totally-basic-94862.html#p730075)

x = 14 + 16 + ... + 64 = (largest + smallest)/2 *(# of terms) = (14 + 64)/2*26 = 39*26.

GCD of 26 and 39*26 is 26.

Answer: C.

P.S. The wording of the question is not quite GMAT-like.
_________________
Target Test Prep Representative
User avatar
D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8048
Location: United States (CA)
Re: If x is a sum of all even integers on the interval 13...65  [#permalink]

Show Tags

New post 06 Feb 2019, 20:44
Maksym wrote:
If x is a sum of all even integers on the interval 13...65 and y is their number, what is the GCD (x, y)?

(A) 1
(B) 13
(C) 26
(D) 52
(E) 1014


The number of even integers from 14 to 64, inclusive, is:

(64 - 14)/2 + 1 = 26 = y

The sum of these integers is:

(64 + 14)/2 * 26 = 39 * 26 = x

Thus, the GCF(x, y) is 26.

Answer: C
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

GMAT Club Bot
Re: If x is a sum of all even integers on the interval 13...65   [#permalink] 06 Feb 2019, 20:44
Display posts from previous: Sort by

If x is a sum of all even integers on the interval 13...65

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





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