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Math Help - [SOLVED] is this possible???

  1. #1
    shosho
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    [SOLVED] is this possible???

    Is it possible to arrange the integers from 1 to 240 in a table with 15 rows and 16 columns so that the sum of the numbers in each of the columns would be the same?

    thanx in advance for your help =)
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by shosho View Post
    Is it possible to arrange the integers from 1 to 240 in a table with 15 rows and 16 columns so that the sum of the numbers in each of the columns would be the same?

    thanx in advance for your help =)
    No. If it were possible and each column sum were x, the the sum of the
    number from 1 to 240 would be 16x, so this sum would be divisible by 16.
    But the sum of the integers from 1 to 240 is 120*241=28920, which is
    not divisible by 16.

    RonL
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  3. #3
    shosho
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    hey thanx

    but im not sure how you got the sum? could you please explain your solution again?
    thanx
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  4. #4
    Grand Panjandrum
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    Quote Originally Posted by shosho View Post
    hey thanx

    but im not sure how you got the sum? could you please explain your solution again?
    thanx
    Let the sum of each column be x, then the total sum is equal to the sum of
    the column sums (that is you add down the coulmns then accross the column
    sums. But this is equal to the sum of the integers from 1 to 240, you are
    supposed to know that the sum of the first n positive integers is

    s=n(n+1)/2,

    So in this case n=240, and s=120 241.

    This should be equal to 15x, but as s is not divisible by 15 no such x exists as
    an integer, so the task is impossible.

    RonL
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