• 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
  • 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
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • 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
  • 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
  • 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

DS question

This topic has 2 expert replies and 0 member replies
prernamalhotra Senior | Next Rank: 100 Posts Default Avatar
Joined
02 Apr 2014
Posted:
44 messages
Followed by:
1 members
Thanked:
2 times

DS question

Post Wed May 14, 2014 1:55 am
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    Of the companies surveyed about the skills they required in prospective employees, 20% required both computer skills and writing skills. What percent of companies surveyed required neither computer skills nor writing skills?

    A) Of those companies surveyed that required computer skills, half required writing skills
    B) 45% of the companies surveyed required writing skills but not computer skills


    Thank you,
    Prerna

    Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
    Post Wed May 14, 2014 2:43 am
    prernamalhotra wrote:
    Of the companies surveyed about the skills they required in prospective employees, 20% required both computer skills and writing skills. What percent of companies surveyed required neither computer skills nor writing skills?

    A) Of those companies surveyed that required computer skills, half required writing skills
    B) 45% of the companies surveyed required writing skills but not computer skills
    This is an EITHER/OR group problem.
    Every company EITHER requires computer skills OR does not.
    Every company EITHER requires writing skills OR does not.
    For an EITHER/OR group problem, we can use a GROUP GRID (also known as a double-matrix) to organize the data.

    Let C = computer skills, NC = not computer skills, W = writing skills, NW = not writing skills.
    In the grids below, the entries in any given row or column must add up to the TOTAL of that row or column.
    Let the total number of companies = 100.

    20% required both computer skills and writing skills:
    ttp://postimg.org/image/btxqkx7ll/" target="_blank">
    The question stem asks for the value of the middle box: the number that require NEITHER type of skill.

    Statement 1: Of those companies surveyed that required computer skills, half required writing skills.
    Thus, the 20 companies in the top left corner of the grid represent half the total number of companies that require computer skills.
    The following grid is yielded:
    ttp://postimg.org/image/bflr8bfzd/" target="_blank">
    No way to determine the value of the middle box.
    INSUFFICIENT.

    Statement 2: 45% of the companies surveyed required writing skills but not computer skills.
    The following grid is yielded:
    ttp://postimg.org/image/6df2qg6gv/" target="_blank">
    No way to determine the value of the middle box.
    INSUFFICIENT.

    Statements combined:
    The following grid is yielded:
    ttp://postimg.org/image/mbmfcetnx/" target="_blank">
    Middle box = 15.
    SUFFICIENT.

    The correct answer is C.

    _________________
    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: prernamalhotra, unknown13
    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.
    Post Wed May 14, 2014 6:54 am
    I thought I'd point out that Mitch's "group grid" approach (aka Double Matrix Method) is a must-have skill for the GMAT, since these kinds of overlapping sets questions are VERY common on the GMAT. In fact, I'll go as far as saying that it's likely that you'll encounter at least one of them on test day.

    We can use this technique for most questions featuring a population in which each member has two characteristics associated with it.
    Here, we have a population of companies, and the two characteristics are:
    - requires computer skills OR does not require computer skills.
    - requires writing skills OR does not require writing skills

    To learn more about the Double Matrix Method, watch our free video: http://www.gmatprepnow.com/module/gmat-word-problems?id=919

    Once you’re familiar with this technique, you can attempt these additional practice questions:

    Easy Problem Solving questions
    - http://www.beatthegmat.com/the-aam-aadmi-party-t272242.html
    - http://www.beatthegmat.com/finance-majors-non-finance-majors-overlapping-set-question-t167425.html

    Medium Problem Solving questions
    - http://www.beatthegmat.com/probability-question-t273360.html
    - http://www.beatthegmat.com/posted-speed-limit-t272374.html
    - http://www.beatthegmat.com/motel-t271938.html
    - http://www.beatthegmat.com/of-the-applicants-passes-a-certain-test-15-t270255.html
    - http://www.beatthegmat.com/opening-night-and-late-patrons-t264869.html
    - http://www.beatthegmat.com/ds-french-japanese-t222297.html

    Difficult Problem Solving questions
    - http://www.beatthegmat.com/ratio-problem-t268339.html
    - http://www.beatthegmat.com/overlapping-sets-question-t265223.html
    - http://www.beatthegmat.com/fractions-t264254.html
    - http://www.beatthegmat.com/overlapping-sets-t264092.html
    - http://www.beatthegmat.com/mba/2011/05/09/random-double-matrix-question-2

    Easy Data Sufficiency questions
    - http://www.beatthegmat.com/for-what-percent-of-those-tested-for-a-certain-t270596.html
    - http://www.beatthegmat.com/ds-quest-t187706.html

    Medium Data Sufficiency questions
    - http://www.beatthegmat.com/sets-matrix-ds-t271914.html
    - http://www.beatthegmat.com/each-of-people-voted-once-in-an-election-x-t271375.html
    - http://www.beatthegmat.com/a-manufacturer-t270331.html
    - http://www.beatthegmat.com/in-costume-for-halloween-t269355.html
    - http://www.beatthegmat.com/mba/2011/05/05/random-double-matrix-question-1

    Difficult Data Sufficiency questions
    - http://www.beatthegmat.com/double-set-matrix-question-t271423.html
    - http://www.beatthegmat.com/sets-t269449.html
    - http://www.beatthegmat.com/mba/2011/05/16/random-double-matrix-question-3

    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

    Thanked by: prernamalhotra
    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 111 topics
    2 ardz24 64 topics
    3 LUANDATO 62 topics
    4 swerve 60 topics
    5 AAPL 57 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

    160 posts
    2 image description EconomistGMATTutor

    The Economist GMAT Tutor

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

    EMPOWERgmat

    122 posts
    4 image description GMATGuruNY

    The Princeton Review Teacher

    122 posts
    5 image description Scott@TargetTestPrep

    Target Test Prep

    118 posts
    See More Top Beat The GMAT Experts