• 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
  • 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
  • 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
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas 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
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • 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

What is the perimeter of a rectangle with length L...

This topic has 1 expert reply and 0 member replies

What is the perimeter of a rectangle with length L...

Post Wed Nov 08, 2017 10:31 am
What is the perimeter of a rectangle with length L and width W?

1) L - W = 15
2) L + W = 35

The OA is B.

Please, can any expert assist me with this DS question? I don't have it clear why that is the correct answer? I appreciate if any explain it for me. Thanks.

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post Wed Nov 08, 2017 6:11 pm
Hi LUANDATO,

We're asked for the perimeter of a rectangle with a length of L and a width of W. You can use a mix of logic and TESTing VALUES to get to the correct answer. Regardless of your approach though, you'll need the formula for perimeter of a rectangle:

Perimeter = 2L + 2W

1) L - W = 15

Fact 1 doesn't provide us with the necessary information to determine the value of 2L + 2W. You can also TEST VALUES to prove the inconsistency:
IF....
L=16, W=1, then the perimeter is 32 + 2 = 34
L=17, W=2, then the perimeter is 34 + 4 = 38
Fact 1 is INSUFFICIENT

2) L + W = 35

Fact 2 gives us the value of L+W. If we double this equation, we'll have...
2L + 2W = 70 and that is the exact value that we're trying to determine. You can also TEST VALUES - and you'll find that the answer is ALWAYS 70.
Fact 2 is SUFFICIENT

Final Answer: B

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

_________________
Contact Rich at Rich.C@empowergmat.com

  • +1 Upvote Post
  • Quote
  • Flag

Top First Responders*

1 GMATGuruNY 70 first replies
2 Rich.C@EMPOWERgma... 42 first replies
3 Brent@GMATPrepNow 40 first replies
4 Jay@ManhattanReview 24 first replies
5 Terry@ThePrinceto... 10 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 GMATGuruNY

The Princeton Review Teacher

133 posts
2 image description Scott@TargetTestPrep

Target Test Prep

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

EMPOWERgmat

111 posts
4 image description Jeff@TargetTestPrep

Target Test Prep

111 posts
5 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

90 posts
See More Top Beat The GMAT Experts