Results 1 to 2 of 2

Math Help - Writing the Numbers till N to form a new number

  1. #1
    Newbie
    Joined
    Mar 2009
    Posts
    1

    Writing the Numbers till N to form a new number

    Can the number obtained by writing the numbers from 1 to n in order (for some n > 1) be the same when read left-to-right and right-to-left?

    say n=11, the number obtained by writhing the numbers from 1 to n in order will be

    1234567891011

    We want to check whether it can be same when read from left to right or right to left and if this is not possible can we prove that it is not possible or it is possible

    I have tried to form an expression which would give the value of new number formed on powers of 10 . I have tried to form this expression for both forward and reverse numbers and try to see of their difference can be 0. But no success.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Opalg's Avatar
    Joined
    Aug 2007
    From
    Leeds, UK
    Posts
    4,041
    Thanks
    7
    Quote Originally Posted by abhi_dude View Post
    Can the number obtained by writing the numbers from 1 to n in order (for some n > 1) be the same when read left-to-right and right-to-left?

    say n=11, the number obtained by writhing the numbers from 1 to n in order will be

    1234567891011

    We want to check whether it can be same when read from left to right or right to left and if this is not possible can we prove that it is not possible or it is possible

    I have tried to form an expression which would give the value of new number formed on powers of 10 . I have tried to form this expression for both forward and reverse numbers and try to see of their difference can be 0. But no success.
    This is a very neat problem. But I'm reluctant to give any hints, because this sounds just like the sort of problem that might be set in a math competition. Can you tell us where the problem comes from, please?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. number of throws till die shows all faces
    Posted in the Statistics Forum
    Replies: 1
    Last Post: August 10th 2011, 02:35 AM
  2. Writing a number in terms of other numbers.
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 15th 2010, 07:31 PM
  3. Writing a number in trigonometric form
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: November 3rd 2009, 05:59 PM
  4. Writing a Complex Number in Trigonometric Form
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: April 13th 2009, 06:02 PM
  5. Writing complex numbers in the form x+ij.
    Posted in the Calculus Forum
    Replies: 2
    Last Post: December 6th 2008, 05:04 AM

Search Tags


/mathhelpforum @mathhelpforum