• 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
  • 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
  • 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
  • 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
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh

factor problem

This topic has 4 member replies
jamesk486 Master | Next Rank: 500 Posts Default Avatar
Joined
28 Mar 2007
Posted:
141 messages
Followed by:
1 members
Thanked:
2 times

factor problem

Post Wed Apr 11, 2007 1:16 am
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    X is a prime and y is a positive integer, How many different factors of (2^3)*(x^y) are there?
    (1) x=5
    (2) y=3

    I got stuck in the middle, after figuring out that the number of factors would be (3+1)(y+1)...but someone told me that x could not be 2 or something like that..anyways i'm pretty lost!

    Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
    ajith Legendary Member
    Joined
    21 Sep 2006
    Posted:
    1275 messages
    Followed by:
    2 members
    Thanked:
    124 times
    Test Date:
    April 2010
    Target GMAT Score:
    740
    Post Thu Apr 12, 2007 1:51 am
    jamesk486 wrote:
    X is a prime and y is a positive integer, How many different factors of (2^3)*(x^y) are there?
    (1) x=5
    (2) y=3

    I got stuck in the middle, after figuring out that the number of factors would be (3+1)(y+1)...but someone told me that x could not be 2 or something like that..anyways i'm pretty lost!
    If 2 is a factor of x the number of factors of (2^3)*(x^y) would not be (3+1)(y+1)

    So we need to know x as well as y to determine the number of factors.

    Smile

    _________________
    Always borrow money from a pessimist, he doesn't expect to be paid back.

    jamesk486 Master | Next Rank: 500 Posts Default Avatar
    Joined
    28 Mar 2007
    Posted:
    141 messages
    Followed by:
    1 members
    Thanked:
    2 times
    Post Thu Apr 12, 2007 6:45 am
    I'm still confused...because I thought the answer would be B but its C...

    RAGS Senior | Next Rank: 100 Posts Default Avatar
    Joined
    18 Mar 2007
    Posted:
    70 messages
    Followed by:
    1 members
    Post Thu Apr 12, 2007 7:12 am
    Well here as u know the no of factors can be found out by getting the no of prime factors as u said (1+3)(y+1)

    statement 1 gives x=5 whickh is not sufficient since u need to know Y

    statement 2 gives y=3
    here consider the case where x=2 then we have no of factors will be
    for 2exp(6) will be (6+1) ie 7
    but for x as any prime other than 2 the ans would be (3+1)(3+1) ie 16

    but both together solves the problem by giving a value to X
    So C

    Cybermusings Legendary Member Default Avatar
    Joined
    27 Mar 2007
    Posted:
    559 messages
    Followed by:
    2 members
    Thanked:
    5 times
    Post Thu Apr 12, 2007 7:25 am
    Thanks RAGS...your explanation has lifted the cloud

    Best Conversation Starters

    1 Vincen 203 topics
    2 Roland2rule 65 topics
    3 lheiannie07 57 topics
    4 ardz24 44 topics
    5 lionsshare 14 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

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

    EMPOWERgmat

    103 posts
    3 image description GMATGuruNY

    The Princeton Review Teacher

    98 posts
    4 image description Jay@ManhattanReview

    Manhattan Review

    95 posts
    5 image description Matt@VeritasPrep

    Veritas Prep

    80 posts
    See More Top Beat The GMAT Experts