tough math problem asking for help

Does anyone have any clue as how to solve following math problem?

Find the number of 5-digit numbers less than 40000 in which the 3 3-digit numbers formed by consecutive digits are all divisible by either 17 or 23. Remember, zero cannot be the first digit in a 3-digit number.

Thanks a lot.

 

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娃在上学,不能试着帮忙。等爱做题的家长来帮你吧:) -怀旧一点点- 给 怀旧一点点 发送悄悄话 怀旧一点点 的博客首页 (0 bytes) () 11/18/2015 postreply 10:19:59

答案是不是不止一个? -超级机器人- 给 超级机器人 发送悄悄话 (451 bytes) () 11/18/2015 postreply 10:43:04

formed by consecutive digits ? -WISEBAO- 给 WISEBAO 发送悄悄话 WISEBAO 的博客首页 (0 bytes) () 11/18/2015 postreply 10:46:08

对啊, abcde, 三个三位数就是abc, bcd, cde, 而不是ade或者其他。 -超级机器人- 给 超级机器人 发送悄悄话 (180 bytes) () 11/18/2015 postreply 10:53:24

Consecutive digits are integers that follow each other in order -WISEBAO- 给 WISEBAO 发送悄悄话 WISEBAO 的博客首页 (0 bytes) () 11/18/2015 postreply 11:04:53

如果是这样,那就无解了。不然,就是13个解。 -超级机器人- 给 超级机器人 发送悄悄话 (174 bytes) () 11/18/2015 postreply 11:07:46

题目问的是有几个 -TZX999- 给 TZX999 发送悄悄话 (158 bytes) () 11/18/2015 postreply 10:54:30

码农,程序算的不算 -满墙红叶- 给 满墙红叶 发送悄悄话 (169 bytes) () 11/18/2015 postreply 10:55:31

13 looks right to me. Thanks so much. Can you share how you got -momoftwok- 给 momoftwok 发送悄悄话 (0 bytes) () 11/18/2015 postreply 11:15:53

我是用程序算的, 算作弊。 就是一个简单的循环(见内) -超级机器人- 给 超级机器人 发送悄悄话 (1352 bytes) () 11/18/2015 postreply 11:18:23

Ha Ha Ha -momoftwok- 给 momoftwok 发送悄悄话 (0 bytes) () 11/18/2015 postreply 11:28:52

23460=17x23x60 -jenifer- 给 jenifer 发送悄悄话 jenifer 的博客首页 (0 bytes) () 11/18/2015 postreply 11:04:03

I used the bruce force and found 8. Hopefully there are smart wa -momoftwok- 给 momoftwok 发送悄悄话 (14252 bytes) () 11/18/2015 postreply 11:08:38

题中给定的17和23是两个素数,素数有很多特别性质 -TZX999- 给 TZX999 发送悄悄话 (74 bytes) () 11/18/2015 postreply 11:15:43

Count by Cases. -dr_yin- 给 dr_yin 发送悄悄话 (738 bytes) () 11/18/2015 postreply 17:30:05

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