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

It is currently 23 Feb 2019, 01:24
Register
GMAT Club Tests
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

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.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar

  • Free GMAT RC Webinar

     February 23, 2019

     February 23, 2019

     07:00 AM PST

     09:00 AM PST

    Learn reading strategies that can help even non-voracious reader to master GMAT RC. Saturday, February 23rd at 7 AM PT
    GMAT: Verbal | GMAT: Quantitative | Free

  • FREE Quant Workshop by e-GMAT!

     February 24, 2019

     February 24, 2019

     07:00 AM PST

     09:00 AM PST

    Get personalized insights on how to achieve your Target Quant Score.
    GMAT: Verbal | GMAT: Quantitative | Free
CLICK HERE TO HIDE/SHOW EVENTS

If x and y are integers, what is the least possible positive value of

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
  Sort by Date Sort by Kudos  
Search for:
 
Print view
First unread post
Author Message
TAGS:

Hide Tags

 
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6985
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
If x and y are integers, what is the least possible positive value of  [#permalink]

Show Tags

New post 03 Sep 2018, 23:27
3
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

84% (01:29) correct 16% (02:15) wrong based on 66 sessions

HideShow timer Statistics

[Math Revolution GMAT math practice question]

If x and y are integers, what is the least possible positive value of 21x+35y?

A. 1
B. 3
C. 5
D. 7
E. 9
Spoiler: OA

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Senior Manager
Senior Manager
User avatar
S
Joined: 07 Oct 2017
Posts: 258
Re: If x and y are integers, what is the least possible positive value of  [#permalink]

Show Tags

New post 03 Sep 2018, 23:41
1
MathRevolution wrote:
[Math Revolution GMAT math practice question]

If x and y are integers, what is the least possible positive value of 21x+35y?

A. 1
B. 3
C. 5
D. 7
E. 9
We need least positive value. That means 35y is greater than 21x
Y will be positive and x will be negative.

Possible values of y= 35,70,105,140,175
Possible values of x= - 21, - 42, - 63, - 84, - 105, - 126, - 147

Least possible POSITIVE value = 70 - 63 = 7

Answer is D
( NOTE : 0 is neither positive nor negative integer. It is just even integer)

Thank you = Kudos
_________________

Thank you =Kudos
The best thing in life lies on the other side of the pain.

CEO
CEO
User avatar
D
Joined: 11 Sep 2015
Posts: 3447
Location: Canada
Re: If x and y are integers, what is the least possible positive value of  [#permalink]

Show Tags

New post 04 Sep 2018, 12:55
1
Top Contributor
MathRevolution wrote:
[Math Revolution GMAT math practice question]

If x and y are integers, what is the least possible positive value of 21x+35y?

A. 1
B. 3
C. 5
D. 7
E. 9


21x + 35y = 7(3x + 5y)

Since x and y are INTEGERS, we know that 3x and 5y are each INTEGERS, which means 3x + 5y equals some integer
So, we can write: 21x + 35y = 7(some integer)
In other words, 21x + 35y is a multiple of 7

Check the answer choices.....only D is a multiple of 7

Answer: D

Cheers,
Brent
_________________

Test confidently with gmatprepnow.com
Image

CEO
CEO
User avatar
D
Joined: 11 Sep 2015
Posts: 3447
Location: Canada
Re: If x and y are integers, what is the least possible positive value of  [#permalink]

Show Tags

New post 04 Sep 2018, 13:04
Top Contributor
MathRevolution wrote:
[Math Revolution GMAT math practice question]

If x and y are integers, what is the least possible positive value of 21x+35y?

A. 1
B. 3
C. 5
D. 7
E. 9


Another approach:

There's a nice rule that says:
If j, k and d are integers, and j is a multiple of d, and k is a multiple of d, then (j+k) must be a multiple of d

21x is a multiple of 7, since 21x = 7(3x)
35y is a multiple of 7, since 35y = 7(5y)

Since 21x and 35y are multiples of 7, the sum 21x + 35y must be a multiple of 7.
Since only 1 answer choice (D) is a multiple of 7, D must be the correct answer.

Cheers,
Brent
_________________

Test confidently with gmatprepnow.com
Image

Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6985
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
Re: If x and y are integers, what is the least possible positive value of  [#permalink]

Show Tags

New post 06 Sep 2018, 00:34
=>

\(21x + 35y = 7*3x + 7*5y = 7(3x+5y)\) is a multiple of \(7\). The smallest positive multiple of \(7\) is \(7\). So, we look for \(x\) and \(y\) such that \(21x + 35y = 7\). This will occur when \(3x + 5y = 1\).
When \(x = 2\) and \(y = -1, 3x + 5y = 3*2 + 5*(-1) = 6 – 5 = 1\), and \(21x + 35y = 7(3x+5y) = 7(1) = 7.\)
Thus, \(7\) is the answer.

Therefore, the answer is D.
Answer: D
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Target Test Prep Representative
User avatar
P
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 4972
Location: United States (CA)
Re: If x and y are integers, what is the least possible positive value of  [#permalink]

Show Tags

New post 07 Sep 2018, 16:20
MathRevolution wrote:
[Math Revolution GMAT math practice question]

If x and y are integers, what is the least possible positive value of 21x+35y?

A. 1
B. 3
C. 5
D. 7
E. 9


Since x and y are integers and 21x + 35y = 7(3x + 5y), we see that the answer must be a multiple of 7. Therefore, D is the correct answer.

Answer: D
_________________

Scott Woodbury-Stewart
Founder and CEO

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

GMAT Club Bot
Re: If x and y are integers, what is the least possible positive value of   [#permalink] 07 Sep 2018, 16:20
Print view
First unread post
Display posts from previous: Sort by

If x and y are integers, what is the least possible positive value of

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

Moderators: chetan2u, Bunuel, VeritasKarishma, Gladiator59, generis

Search for:


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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions