回複：回複：回複：5/36

來源: 於 2010-02-07 22:20:10 [舊帖] [給我悄悄話] 本文已被閱讀：次

The 1/4 for add numbers is wrong. Should be:
1/2 + 1/36 = 19/36 --- for one odd, one even number, plus (1, 1).
so the anser is:
19/36 - 1/9 = 5/12.