Results 1 to 2 of 2

Math Help - Worded Problem - Difficult to solve

  1. #1
    Newbie
    Joined
    Nov 2012
    From
    melbourne, australia
    Posts
    4

    Worded Problem - Difficult to solve

    Terry has invented a new way to extend lists of numbers. To Terryfy a list such as [1, 8] he creates two lists [2, 9] and [3, 10], where each term is one more than the corresponding term in the previous list, and then joins the three lists together to give [1, 8, 2, 9, 3, 10]. If he starts with a list containing one number [0] and repeatedly Terryfies it he creates the list.

    [0, 1, 2, 1, 2, 3, 2, 3, 4, 1, 2, 3, 2, 3, 4, 3, 4, 5, 2, 3, 4...].

    What is the 2012th number in this Terryfic list?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member jakncoke's Avatar
    Joined
    May 2010
    Posts
    387
    Thanks
    80

    Re: Worded Problem - Difficult to solve

    The 2012 number is 1283. Note this could be described by the function, which tells us the number at position x in the sequence, f(x) = x mod 3^n where n = floor[x/3].

    Think of this problem like a counter, which grows by size 3^n, the first set {0} = 3^0 = 1
    The second set {0, 1, 2} = 3^1
    The third set {0, 1, 2, 1, 2, 3, 2, 3, 4} = 3^2
    ....

    As soon as the counter resets, At 3^0 , 3^1, 3^2, we me make it bigger 3^(n+1), and start counting again from 0 till the counter resets, that is at 3^(n+1)
    Last edited by jakncoke; November 9th 2012 at 05:35 PM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Worded problem - get equation and solve.
    Posted in the Algebra Forum
    Replies: 2
    Last Post: April 19th 2011, 12:53 PM
  2. Two difficult solve for x qns.
    Posted in the Algebra Forum
    Replies: 7
    Last Post: January 7th 2010, 04:24 AM
  3. Replies: 5
    Last Post: September 12th 2009, 08:42 PM
  4. Replies: 2
    Last Post: September 12th 2009, 08:08 PM
  5. Worded max/min problem
    Posted in the Calculus Forum
    Replies: 2
    Last Post: February 28th 2009, 02:50 AM

Search Tags


/mathhelpforum @mathhelpforum