• Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh

The positive two-digit integers x and y

This topic has 2 expert replies and 0 member replies
boomgoesthegmat Senior | Next Rank: 100 Posts Default Avatar
Joined
25 Apr 2016
Posted:
93 messages
Upvotes:
1

The positive two-digit integers x and y

Post Tue May 03, 2016 2:39 pm
The positive two-digit integers x and y have the same digits, but in reverse order. Which of the following must be a factor of x + y?

A) 6
B) 9
C) 10
D) 11
E) 14

OA: D

  • +1 Upvote Post
  • Quote
  • Flag
Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
Top Reply
Post Tue May 03, 2016 7:50 pm
Hi boomgoesthegmat,

This question is perfect for TESTing VALUES (as Brent's approach shows). One of the great aspects about this question is that there are a variety of options that you can use to find the correct answer.

Brent ended up using 12 and 21, for a total of 33

But you could also use…
25 and 52, for a total of 77
13 and 31, for a total of 44
23 and 32, for a total of 55
Etc.

Final Answer: D

GMAT assassins aren't born, they're made,
Rich

_________________
Contact Rich at Rich.C@empowergmat.com

  • +1 Upvote Post
  • Quote
  • Flag
Top Reply
Post Tue May 03, 2016 2:56 pm
boomgoesthegmat wrote:
The positive two-digit integers x and y have the same digits, but in reverse order. Which of the following must be a factor of x + y?

A) 6
B) 9
C) 10
D) 11
E) 14

OA: D
The question asks is to find what MUST be true.

So, a quick and simple solution is to TEST some values. If a statement turns out to be FALSE, we can eliminate that answer choice.

Let x = 12 and let y = 21
So, x + y = 12 + 21 = 33

Now check the answer choices.
A) 6 is not a factor of 33. ELIMINATE A
B) 9 is not a factor of 33. ELIMINATE B
C) 10 is not a factor of 33. ELIMINATE C
D) 11 IS a factor of 33. KEEP D
E) 14 is not a factor of 33. ELIMINATE E

Answer: D

Cheers,
Brent

_________________
Brent Hanneson – Founder of GMATPrepNow.com
Use our video course along with Beat The GMAT's free 60-Day Study Guide

Check out the online reviews of our course
Come see all of our free resources

  • +1 Upvote Post
  • Quote
  • Flag
GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMAT’s FREE 60-Day Study Guide and reach your target score in 2 months!

Best Conversation Starters

1 lheiannie07 120 topics
2 LUANDATO 62 topics
3 swerve 62 topics
4 ardz24 61 topics
5 AAPL 57 topics
See More Top Beat The GMAT Members...

Most Active Experts

1 image description Scott@TargetTestPrep

Target Test Prep

174 posts
2 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

173 posts
3 image description Rich.C@EMPOWERgma...

EMPOWERgmat

131 posts
4 image description Jeff@TargetTestPrep

Target Test Prep

130 posts
5 image description EconomistGMATTutor

The Economist GMAT Tutor

130 posts
See More Top Beat The GMAT Experts