回複：讓人煩惱的禮金卡問題

來源: 於 2009-01-02 21:31:57 [舊帖] [給我悄悄話] 本文已被閱讀：次

For first time, make a guess $1000/(1+10%)~909. Next time, take another factor of 1/(1+10%), etc.