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

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • 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

Unable to proceed after calculating x. Help.

This topic has 1 expert reply and 4 member replies
aman88 Master | Next Rank: 500 Posts Default Avatar
Joined
20 Oct 2012
Posted:
142 messages
Followed by:
3 members
Thanked:
20 times
Target GMAT Score:
700

Unable to proceed after calculating x. Help.

Post Fri Dec 14, 2012 7:47 am
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    The interior of a rectangular carton is designed by a certain manufacturer to have a volume of x cubic feet and a ratio of length to width to height of 3 : 2 : 2. In terms of x, which of the following equals the height of the carton, in feet?

    A. Cube root x
    B. Cube root (2x/3)
    C. Cube root (3x/2)
    D. 2/3 (Cube root x)
    E. 3/2(Cube root x)

    OA: B

    3y*2y*2y = x (given)
    12y^3 = x
    y = cube root(x/12)

    Inserting this value of y in 2y...
    H = 2y
    H = 2*{cube root(x/12)}

    I am stuck after this. How do I proceed?

    Thanks.

    Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
    Anindya Madhudor Senior | Next Rank: 100 Posts Default Avatar
    Joined
    12 Nov 2012
    Posted:
    85 messages
    Followed by:
    2 members
    Thanked:
    8 times
    Post Fri Dec 14, 2012 7:53 am
    Take 2 inside the cube root. Then,

    H = cube root(8x/12) = cube root(2x/3)

    Thanked by: aman88
    Post Fri Dec 14, 2012 9:04 am
    aman88 wrote:
    The interior of a rectangular carton is designed by a certain manufacturer to have a volume of x cubic feet and a ratio of length to width to height of 3 : 2 : 2. In terms of x, which of the following equals the height of the carton, in feet?

    A. Cube root x
    B. Cube root (2x/3)
    C. Cube root (3x/2)
    D. 2/3 (Cube root x)
    E. 3/2(Cube root x)

    OA: B
    Let L=3, W=2 and H=2.
    x = volume = 3*2*2 = 12.
    The question stem asks for the value of H=2. This is our target.
    Now we plug x=12 into the answers to see which yields our target of 2.
    A quick scan of the answer choices reveals that only B works:
    (2/3 * x )^(1/3) = (2/3 * 12)^(1/3) = 8^(1/3) = 2.

    The correct answer is B.

    _________________
    Mitch Hunt
    GMAT Private Tutor
    GMATGuruNY@gmail.com
    If you find one of my posts helpful, please take a moment to click on the "Thank" icon.
    Available for tutoring in NYC and long-distance.
    For more information, please email me at GMATGuruNY@gmail.com.

    Thanked by: aman88
    Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now.
    aman88 Master | Next Rank: 500 Posts Default Avatar
    Joined
    20 Oct 2012
    Posted:
    142 messages
    Followed by:
    3 members
    Thanked:
    20 times
    Target GMAT Score:
    700
    Post Fri Dec 14, 2012 10:40 am
    Anindya Madhudor wrote:
    Take 2 inside the cube root. Then,

    H = cube root(8x/12) = cube root(2x/3)
    Anindya, can you please explain this? How did we take "2 inside the cube root"?

    Thanks.

    Anindya Madhudor Senior | Next Rank: 100 Posts Default Avatar
    Joined
    12 Nov 2012
    Posted:
    85 messages
    Followed by:
    2 members
    Thanked:
    8 times
    Post Fri Dec 14, 2012 10:45 am
    2 is equal to cube root of 8.

    So, the expression "cube root(8x/12)" is equal to "2 * cube root(x/12)". Think of this in the reverse way. If you are given "cube root(8x/12)", can you write this as "2 * cube root(x/12)"? The answer is yes, you can. So, the opposite is true as well.

    Thanked by: aman88
    ritind Senior | Next Rank: 100 Posts
    Joined
    21 Nov 2012
    Posted:
    47 messages
    Thanked:
    4 times
    Test Date:
    07/02/2013
    Target GMAT Score:
    750
    Post Wed Dec 19, 2012 2:39 am
    Ver simple approach
    Lets assume that the following are the dimensions of the rectangle
    Length = 3, Width = 2, Height = 2
    These figures comply with the ratio given in the ques.
    Vol = 3*2*2 = 12

    Cube root of 12 gives decimal value whereas the height that we have taken is an integer.
    This eliminates A, D and E
    Insert the value in B

    cube root((2*12)/3) = 2 and voila B is the option

    Best Conversation Starters

    1 Vincen 180 topics
    2 lheiannie07 61 topics
    3 Roland2rule 54 topics
    4 ardz24 44 topics
    5 VJesus12 14 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

    155 posts
    2 image description Rich.C@EMPOWERgma...

    EMPOWERgmat

    105 posts
    3 image description GMATGuruNY

    The Princeton Review Teacher

    101 posts
    4 image description Jay@ManhattanReview

    Manhattan Review

    82 posts
    5 image description Matt@VeritasPrep

    Veritas Prep

    80 posts
    See More Top Beat The GMAT Experts