GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 19 Feb 2020, 09:55

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 positive integer such that x^2 is a multiple of 56, what is

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

Hide Tags

Find Similar Topics 
Intern
Intern
avatar
Joined: 23 Jan 2020
Posts: 1
If x is a positive integer such that x^2 is a multiple of 56, what is  [#permalink]

Show Tags

New post 23 Jan 2020, 05:33
3
1
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (01:34) correct 0% (00:00) wrong based on 8 sessions

HideShow timer Statistics

If x is a positive integer such that x^2 is a multiple of 56, what is the least possible value of x?
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 61302
Re: If x is a positive integer such that x^2 is a multiple of 56, what is  [#permalink]

Show Tags

New post 23 Jan 2020, 05:42
1
cristinaolt19 wrote:
If x is a positive integer such that x^2 is a multiple of 56, what is the least possible value of x?


x^2 = 56k
x^2 = 2^3*7*k
k must make powers of 2 and 7 even, so that 2^3*7*k becomes a perfect square. The least value of k is therefore 2*7.

So, x^2 = 2^3*7*k = 2^4*7^2.
x = 2^2*7.

P.S. We have specific rules of posting a question on the forum: https://gmatclub.com/forum/rules-to-pos ... 08733.html Please read and edit the first post: provide the source, options and the OA. Thank you.
_________________
Director
Director
User avatar
V
Joined: 28 Jul 2016
Posts: 855
Location: India
Concentration: Finance, Human Resources
GPA: 3.97
WE: Project Management (Investment Banking)
Reviews Badge
Re: If x is a positive integer such that x^2 is a multiple of 56, what is  [#permalink]

Show Tags

New post 28 Jan 2020, 19:28
cristinaolt19 wrote:
If x is a positive integer such that x^2 is a multiple of 56, what is the least possible value of x?


\(56 = 8*7\)
or \(2^3 *7\)
thus x^2 should atleast have factors of the form \(2^3 *7\)
and since x an integer \(x^2\) should be a perfect square
thus \(x^2\) should be of the form \(2^4 *7^2\)
or\( x = 2^2*7\)
= 28
_________________

Keep it simple. Keep it blank
Senior Manager
Senior Manager
avatar
G
Joined: 16 Feb 2015
Posts: 355
Location: United States
Re: If x is a positive integer such that x^2 is a multiple of 56, what is  [#permalink]

Show Tags

New post 28 Jan 2020, 19:35
Do these types of questions belong to the GMAT exam? I have doubt Bunuel.
Please clarify, if it is, where can we practice this type of questions.
Director
Director
User avatar
V
Joined: 28 Jul 2016
Posts: 855
Location: India
Concentration: Finance, Human Resources
GPA: 3.97
WE: Project Management (Investment Banking)
Reviews Badge
Re: If x is a positive integer such that x^2 is a multiple of 56, what is  [#permalink]

Show Tags

New post 28 Jan 2020, 19:38
rajatchopra1994 wrote:
Do these types of questions belong to the GMAT exam? I have doubt Bunuel.
Please clarify, if it is, where can we practice this type of questions.


We have similar questions in OG . Yeah the format of question is incorrect. Missing things are options in this questions.
_________________

Keep it simple. Keep it blank
VP
VP
User avatar
V
Joined: 11 Feb 2015
Posts: 1029
Re: If x is a positive integer such that x^2 is a multiple of 56, what is  [#permalink]

Show Tags

New post 28 Jan 2020, 20:55
cristinaolt19 wrote:
If x is a positive integer such that x^2 is a multiple of 56, what is the least possible value of x?


x^2 = 56k

x^2 = 2^3 * 7 * k

Which means k has to be at minimum 2*7

Therefore x is 2^2 * 7 = 28 (Ans)
_________________
________________
Manish :geek:

"Only I can change my life. No one can do it for me"
Target Test Prep Representative
User avatar
V
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 9426
Location: United States (CA)
Re: If x is a positive integer such that x^2 is a multiple of 56, what is  [#permalink]

Show Tags

New post 29 Jan 2020, 04:57
1
cristinaolt19 wrote:
If x is a positive integer such that x^2 is a multiple of 56, what is the least possible value of x?


Since x^2/56 = integer, we need to find the smallest perfect square that is a multiple of 56 or 2^3 * 7. That perfect square is 2^4 * 7^2, so x = 2^2 * 7^1 = 28.
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
181 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 positive integer such that x^2 is a multiple of 56, what is   [#permalink] 29 Jan 2020, 04:57
Display posts from previous: Sort by

If x is a positive integer such that x^2 is a multiple of 56, what is

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





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