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Math Help - Solving 0.9^N = N / 36

  1. #1
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    Solving 0.9^N = N / 36

    Hi,

    Can anyone help me figure out how to re-arrange 0.9^N = N /36 to get the value of N?

    I'm driving myself nuts trying to remember my high school maths.

    Many thanks,

    Nick
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  2. #2
    Super Member
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    Wow , it is very difficult to solve by our hands ! By using my calculator , i got  N \approx 11.13621076
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  3. #3
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    D'oh! I just realised I put the initial formula in slightly wrong, it should be 1 - 0.9^N = N/36.

    Is it not possible to easily re-arrange this?

    Thanks

    Nick
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  4. #4
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    Then N will be zero
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  5. #5
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    May 2010
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    Thanks - I didn't even notice that N = 0 would be a solution!

    The equation has come up as I posed a question to myself asking after how many months a reducing balance depreciation methodology (accounting related) would have depreciated a piece of equipment as much as a straight line depreciation methodology.

    It has another solution where N > 0 that is approximately 35.1 (found by using a spreadsheet), which is the solution I was aiming to explain by re-arranging the equation.

    I'm quite glad it wasn't just a simple re-arrangement and that I'm (hopefully) not missing a basic trick!

    Nick
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