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

divisible by 2, 3, and 15

This topic has 3 member replies

GMAT/MBA Expert

sanju09 GMAT Instructor
Joined
21 Jan 2009
Posted:
3580 messages
Followed by:
70 members
Thanked:
242 times
GMAT Score:
760
Most Active Expert Most Responsive Expert
divisible by 2, 3, and 15 Post Thu Nov 17, 2011 3:16 am
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    If k is divisible by 2, 3, and 15, which of the following is also divisible by these numbers?
    (A) k + 5
    (B) k + 15
    (C) k + 20
    (D) k + 30
    (E) k + 45

    _________________
    “The most important thing in business is honesty, integrity, hard work… family… never forgetting where we came from.”

    “The loudest one in the room is the weakest one in the room.”

    ~Frank Lucas

    facebook

    https://www.facebook.com/pages/The-Princeton-Review-Lucknow/153205671537507


    Sanjeev K Saxena
    Quantitative Instructor
    The Princeton Review - Manya Abroad
    Lucknow-226001
    Tel: +91-522- 6002178
    Cell:+91-9670999928
    www.manyagroup.com

    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.
    neelgandham Community Manager
    Joined
    13 May 2011
    Posted:
    1060 messages
    Followed by:
    49 members
    Thanked:
    313 times
    Test Date:
    October 15th 2012
    Target GMAT Score:
    740
    Post Thu Nov 17, 2011 3:20 am
    sanju09 wrote:
    If k is divisible by 2, 3, and 15, which of the following is also divisible by these numbers?
    (A) k + 5
    (B) k + 15
    (C) k + 20
    (D) k + 30
    (E) k + 45
    k is divisible by 2, 3, and 15, so for k + x to be divisible by these numbers x should also be divisible by all these numbers.From the options, only 20 and 30 are divisible by 2, and only 30 is divisible by 3(between 20 and 30), so Option D - k+30

    _________________
    Anil Gandham
    Welcome to BEATtheGMAT
    My Quant Blog | Photography | Getting Started | BTG Community rules | MBA Watch
    Check out GMAT Prep Now’s online course at http://www.gmatprepnow.com/



    Last edited by neelgandham on Thu Nov 17, 2011 3:22 am; edited 1 time in total

    kmittal82 GMAT Destroyer!
    Joined
    05 Jul 2010
    Posted:
    324 messages
    Followed by:
    3 members
    Thanked:
    68 times
    Target GMAT Score:
    720+
    Post Thu Nov 17, 2011 3:20 am
    I'm sure there's an "algebraic" way of doing this, but its much simpler to test it with k = 30 (which is the lowest k divisible by 2,3 and 15)

    Plugging k = 30, (D) is the only option which is still divisible by 2,3 and 15

    Abhishek009 GMAT Destroyer!
    Joined
    11 Mar 2009
    Posted:
    331 messages
    Followed by:
    1 members
    Thanked:
    43 times
    Target GMAT Score:
    700+
    Post Thu Nov 17, 2011 6:52 am
    sanju09 wrote:
    If k is divisible by 2, 3, and 15, which of the following is also divisible by these numbers?
    (A) k + 5
    (B) k + 15
    (C) k + 20
    (D) k + 30
    (E) k + 45
    2 , 3 and 15 are co prime numbers...

    Now to find the least common no which is divisible by 2, 3 and 15 we take the LCM of the numbers which is 30....

    Hence k = 30

    Again we need to find the number , divisible by the no's will be by checking the options individually -

    A. 30 +5 which is not divisible by 2 and 3

    B. 30+15 which is not divisible by 2 and 3

    C. 30+20 which is not divisible by 2 and 3

    D. 30 + 30 which is divisible by 2 and 3 and 15...

    Hence answer will be D..

    _________________
    Abhishek

    Best Conversation Starters

    1 abhasjha 42 topics
    2 shibsriz@gmail.com 32 topics
    3 phanikpk 18 topics
    4 prernamalhotra 13 topics
    5 qwerty12321 13 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description GMATGuruNY

    The Princeton Review Teacher

    174 posts
    2 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

    165 posts
    3 image description ceilidh.erickson

    Manhattan GMAT Teacher

    47 posts
    4 image description CriticalSquareMBA

    Critical Square

    36 posts
    5 image description lunarpower

    Manhattan GMAT Teacher

    31 posts
    See More Top Beat The GMAT Experts