回複：趁兩高手在,再請教兩個題目...最要命的是我連題目都沒看懂

question 1.
Of the three-digit integers greater than 700
means digits from 701 to 999.

Break 701 to 999 into 3 parts as
part1: 701 to 799
part2: 800 to 899
part3: 900 to 999

Working on part 1,
1) for the range of 701 to 710
701, 702, 703, 704, 705, 706, 707, 708, 709, 710
you find 707 is the one, which are equal to each other and the remaining digit different from the other two.

2. for the range 711 to 720, you have 711 and 717
3. for the range 721 to 730, you have 722 and 727
4. for the range 731 to 740, you have 733 and 737
5. for the range 741 to 750, you have 744 and 747
6. for the range 751 to 760, you have 755 and 757
7. for the range 761 to 770, you have 766 and 767, 770
8. for the range 771 to 780, you have
771,772,773,774,775,776,778,779
9. for the range 781 to 790, you have 788 and 787
10 for the range 791 to 800, you have 800 and 797,799

So for part 1,you have 27

所有跟帖： 

• 非常清楚,謝謝 -陶陶樂，樂陶陶- ♀ (41 bytes) () 12/06/2009 postreply 13:10:42

• 老任是個好教授 -bearsback- ♂ (28 bytes) () 12/06/2009 postreply 14:13:08

• 回複：老任是個好教授 -not.me- ♀ (0 bytes) () 12/06/2009 postreply 15:24:15

• 連頭發絲都數盡了,也沒做出來.真後悔當年隻開除熱機沒去下圍棋。 -not.me- ♀ (0 bytes) () 12/06/2009 postreply 15:28:57

• 無語 -bearsback- ♂ (26 bytes) () 12/06/2009 postreply 16:00:33

• 你真聰明。我還是很迷糊。任老師是我們數學係的退休教授。 -not.me- ♀ (0 bytes) () 12/06/2009 postreply 15:31:14

• 原來如此,今天真幸運 -陶陶樂，樂陶陶- ♀ (0 bytes) () 12/06/2009 postreply 15:35:33

• 一點不錯。任我為不光數學好，武功也好。好好拜山頭學藝吧。 -not.me- ♀ (0 bytes) () 12/06/2009 postreply 15:42:29

• 那一定的... -陶陶樂，樂陶陶- ♀ (0 bytes) () 12/06/2009 postreply 15:59:15

• 也拜這位 NOT。ME 女俠 能學到不少東西 -23731241- ♂ (0 bytes) () 12/06/2009 postreply 16:01:22

• 其實,這裏真正的高人是上麵這為數字先生.你能看懂這寫數字的玄機嗎？ -not.me- ♀ (0 bytes) () 12/06/2009 postreply 16:14:34

• 看不懂,本來對數字就沒天分... -陶陶樂，樂陶陶- ♀ (0 bytes) () 12/06/2009 postreply 16:21:57

• haha，俺不敢說，說了他會把我撕成碎片的：） -not.me- ♀ (0 bytes) () 12/06/2009 postreply 16:29:17

• 我探訪多年楞沒找到解。不怕，說吧，姐BACK UP你。 -念親- ♀ (66 bytes) () 12/06/2009 postreply 19:05:00

• 我隻開個頭:餓-死俺-氣-死俺-1-2-4-1後麵４個自己想吧：） -not.me- ♀ (0 bytes) () 12/06/2009 postreply 19:17:44

• 密碼，要罵就罵２姐吧，不怪我。haha -not.me- ♀ (0 bytes) () 12/06/2009 postreply 19:19:07

• 唉，你這個丫頭片子... -念親- ♀ (160 bytes) () 12/06/2009 postreply 19:43:01

• haha, ２姐說的更逗。我學一會兒去了。 -not.me- ♀ (0 bytes) () 12/06/2009 postreply 19:48:57

• 88 -念親- ♀ (0 bytes) () 12/06/2009 postreply 19:54:14

• 真厲害！我想了７個小時，還是不會做。 -not.me- ♀ (0 bytes) () 12/06/2009 postreply 15:32:43