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

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider

Is b < 0?

This topic has 1 expert reply and 1 member reply
james Junior | Next Rank: 30 Posts Default Avatar
Joined
05 Oct 2014
Posted:
17 messages

Is b < 0?

Post Wed Oct 08, 2014 9:32 pm
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    is b<0?

    (i) b is a multiple of 13
    (ii) b^3 < 13

    Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
    Post Wed Oct 08, 2014 9:46 pm
    Hi james,

    This question is perfect for TESTing Values:

    We're asked if B < 0. This is a YES/NO question.

    Fact 1: B is a multiple of 13.

    By definition, a multiple can be positive, negative or 0.

    So B could be….
    13(1) = 13 Positive results gives us a NO answer
    13(2) = 26
    etc.

    13(0) = 0 "Null" result gives us a NO answer

    13(-1) = -13 Negative results give us a YES answer
    13(-2) = -26
    etc.
    Fact 1 is INSUFFICIENT.

    Fact 2: B^3 < 13

    Here we have no restrictions on "multiples", so any number that fits this restriction will do…

    If….
    B = 1, then the answer is NO
    B = -1, then the answer is YES
    Fact 2 is INSUFFICIENT

    Combined, we know…
    B is a multiple of 13
    B^3 < 13

    If B = 0, then the answer to the question is NO
    If B = -13, then the answer to the question is YES
    Combined, INSUFFICIENT

    Final Answer: E

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

    _________________
    Contact Rich at Rich.C@empowergmat.com

    Post Fri Oct 10, 2014 5:04 am
    james wrote:
    Is b < 0?

    (i) b is a multiple of 13
    (ii) b³ < 13
    Target question: Is b negative?

    Statement 1: b is a multiple of 13
    Here are some multiples of 13: ....-39, -26, -13, 0, 13, 26, 39,...
    As you can seem there are several values of b that satisfy the given condition. Let's examine two of them that yield CONFLICTING answers to the target question:
    Case a: b = -13, in which case b IS negative
    Case b: b = 0, in which case b is NOT negative
    Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

    Statement 2: b³ < 13
    There are several values of b that satisfy this condition. Here are two:
    Case a: b = -1, in which case b IS negative
    Case b: b = 0, in which case b is NOT negative
    Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

    Statements 1 and 2 combined
    There are still several values of b that satisfy BOTH conditions. Here are two:
    Case a: b = -13, in which case b IS negative
    Case b: b = 0, in which case b is NOT negative
    KEY TAKEAWAY: 0 is a multiple of all integers
    Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

    Answer = E

    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

    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 LUANDATO 138 topics
    2 lheiannie07 91 topics
    3 Roland2rule 79 topics
    4 AAPL 71 topics
    5 swerve 66 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description EconomistGMATTutor

    The Economist GMAT Tutor

    160 posts
    2 image description Jay@ManhattanReview

    Manhattan Review

    128 posts
    3 image description GMATGuruNY

    The Princeton Review Teacher

    125 posts
    4 image description Rich.C@EMPOWERgma...

    EMPOWERgmat

    118 posts
    5 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

    114 posts
    See More Top Beat The GMAT Experts