Welcome! Check out our free B-School Guides to learn how you compare with other applicants.
Login or Register

intergers

This topic has 3 member replies
saadiagha Just gettin' started!
Joined
08 Nov 2012
Posted:
19 messages
intergers Post Fri Dec 21, 2012 11:50 am
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    For every even positive integer m,f(m)represents the product of all even integers from 2 to m inclusive. for example f(12)= 2.4.6.8.10.12
    What is the greatest prime factor of f(24)

    I got the correct answer but my working was different. Any ideas if there is more than one correct way of answering this?

    Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
    puneetkhurana2000 Really wants to Beat The GMAT! Default Avatar
    Joined
    14 Nov 2012
    Posted:
    131 messages
    Followed by:
    2 members
    Thanked:
    39 times
    Test Date:
    01/12/2013
    Target GMAT Score:
    700+
    GMAT Score:
    NA
    Post Fri Dec 21, 2012 2:46 pm
    The answer is 11 because f(24) contains 22(2*11) and 13 is not a possibility.

    saadiagha Just gettin' started!
    Joined
    08 Nov 2012
    Posted:
    19 messages
    Post Fri Dec 21, 2012 2:51 pm
    can I multiply 22.24, since they are the highest integers, and then factorize? Or will I be violating a principle doing that?

    puneetkhurana2000 Really wants to Beat The GMAT! Default Avatar
    Joined
    14 Nov 2012
    Posted:
    131 messages
    Followed by:
    2 members
    Thanked:
    39 times
    Test Date:
    01/12/2013
    Target GMAT Score:
    700+
    GMAT Score:
    NA
    Post Fri Dec 21, 2012 3:06 pm
    There is no need to do that because even after multiplication and then factorization as suggested by you the greatest prime factor will be 11 only.

    So, I don't see a point.

    E.g.
    Greatest prime factor of 1*2*3 is 3
    or
    Greatest prime factor of 6 (which has 1,2,3,6 as factors) is also 3.

    Hope this makes sense!!!

    Best Conversation Starters

    1 rommysingh 47 topics
    2 yass20015 30 topics
    3 tapanmittal 13 topics
    4 rakaisraka 12 topics
    5 j_shreyans 12 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description Rich.C@EMPOWERgma...

    EMPOWERgmat

    155 posts
    2 image description GMATGuruNY

    The Princeton Review Teacher

    153 posts
    3 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

    132 posts
    4 image description DavidG@VeritasPrep

    Veritas Prep

    67 posts
    5 image description Max@Math Revolution

    Math Revolution

    63 posts
    See More Top Beat The GMAT Experts