• NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    Hundreds of Questions Highly Detailed Reporting Expert Explanations TAKE A FREE GMAT QUIZ
  • 7 CATs FREE!
    If you earn 100 Forum Points

    Engage in the Beat The GMAT forums to earn
    100 points for $49 worth of Veritas practice GMATs FREE

    Veritas Prep
    VERITAS PRACTICE GMAT EXAMS
    Earn 10 Points Per Post
    Earn 10 Points Per Thanks
    Earn 10 Points Per Upvote
    REDEEM NOW

A rectangular with dimensions 24 inches by 42 inches . . .

This topic has 2 expert replies and 0 member replies

Top Member

A rectangular with dimensions 24 inches by 42 inches . . .

Post
A rectangular with dimensions 24 inches by 42 inches is to be divided into squares of equal size. Which of the following could be a length of a side of the squares?

a) 4 inches
b) 6 inches
c) 7 inches
d) 8 inches
e) 10 inches

The OA is B.

How can I find the correct answer? Can any expert give me some help? Please.

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post
Hello Vincen.

Let's take a look at your question.

We need to divide the rectangle in many squares of equal size. The dimensions are 24 by 42 inches.

We just need to calculate the greatest common factor of 24 and 42. So $$24=2^3\cdot3\ and\ 42=2\cdot3\cdot7.$$ Then $$GCF\left(24,42\right)=2\cdot3=6.$$ SO, we can divide the rectangle in squares of side 2 inches, 3 inches or 6 inches.

As 2 inches and 3 inches are not in the options, the correct option is B .

I hope this explanation may help you. Regards.

_________________
GMAT Prep From The Economist
We offer 70+ point score improvement money back guarantee.
Our average student improves 98 points.

  • +1 Upvote Post
  • Quote
  • Flag
Free 7-Day Test Prep with Economist GMAT Tutor - Receive free access to the top-rated GMAT prep course including a 1-on-1 strategy session, 2 full-length tests, and 5 ask-a-tutor messages. Get started now.

GMAT/MBA Expert

Elite Legendary Member
Joined
23 Jun 2013
Posted:
10197 messages
Followed by:
497 members
Upvotes:
2867
GMAT Score:
800
Post
Hi Vincen,

We're told that a rectangular with dimensions 24 inches by 42 inches is to be divided into SQUARES of EQUAL size. We're asked to find the answer that COULD be a length of a side of the squares. We can solve this question by TESTing THE ANSWERS.

To start, the word 'could' means that there's more than one possible answer - but only one of the five answer choices will 'fit' what we're told. We're thinking about SQUARES and we're meant to use the ENTIRE rectangle - so there can't be any 'leftover' space. Thus, whatever the dimension of the square ends up being, a multiple of that dimension MUST cover the entire 24 inches and 42 inches of the rectangle.

Only 3 of the answer choices divide evenly into 24 (4, 6 and 8). Eliminate Answers C and E.
Of those 3 remaining answers, only one divides evenly into 42 (6). Eliminate Answers A and D.
Thus, the squares must be 6x6 --> and that would yield 28 squares in the given rectangle (these last couple of steps are technically unnecessary, but prove the correct answer).

Final Answer: B

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

_________________
Contact Rich at Rich.C@empowergmat.com

  • +1 Upvote Post
  • Quote
  • Flag
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • 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
  • 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
  • The Princeton Review
    FREE GMAT Exam
    Know how you'd score today for $0

    Available with Beat the GMAT members only code

    MORE DETAILS
    The Princeton Review
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep

Top First Responders*

1 Ian Stewart 41 first replies
2 Brent@GMATPrepNow 36 first replies
3 Scott@TargetTestPrep 33 first replies
4 Jay@ManhattanReview 30 first replies
5 GMATGuruNY 23 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 image description Scott@TargetTestPrep

Target Test Prep

159 posts
2 image description Max@Math Revolution

Math Revolution

91 posts
3 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

56 posts
4 image description Ian Stewart

GMATiX Teacher

50 posts
5 image description GMATGuruNY

The Princeton Review Teacher

35 posts
See More Top Beat The GMAT Experts