紅髮傑克 發問時間: 教育與參考考試 · 1 0 年前

複利問題請各路英雄幫忙

A deposits 10 today and another 30 in five years into a fund paying simple interest of 11% per year. B will make the same two deposits,but the 10 will be deposited n years from today and the 30 will be deposited 2n years from today. B的 deposits earn an annual effective rate of 9.15%. At the end of 10 years, the accumulated value of B的 deposits equals the accumulated value of A的 deposits. Calculate n.

1 個解答

評分
  • 永滅
    Lv 5
    1 0 年前
    最佳解答

    10*(1+10*11%)+30*(1+5*11%)

    =10*(1+9.15%)10-n+30*(1+9.15%)10-2n

    經過一些運算之後,另X=(1.0915)n可以寫成以下形式

    28.1233X2-10X-30=0

    最後可得X=1.2258,代回X=(1.0915)n

    兩邊取ln,可得n=2.325431953

    答案可能會寫些微誤差~~因為有四捨五入

    2009-04-02 14:49:10 補充:

    電腦顯示的不好

    X=(1.0915)^n

    別誤解

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