The Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.


Math Forum » Discussions » sci.math.* » sci.math

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: One Through Nine, With Eight Missing, And Two Ones
Replies: 19   Last Post: Mar 31, 2011 5:11 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Dan Hoey

Posts: 172
Registered: 12/6/04
Re: One Through Nine, With Eight Missing, And Two Ones
Posted: Mar 24, 2011 9:12 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On 3/24/2011 1:37 PM, Leroy Quet wrote:
> The solution -- except reflections and rotations -- can be seen to be
> unique by first noting that, due to the evenness and oddness of the
> numbers, the three even numbers must be in some order along a main
> diagonal.


Neat. So combining the two ideas (even diagonal and 9 triples) there
are only nine cases, all but one of which yield quick contradictions.

2 9 7 2 9 7 4 9 5 4 9 5 6 9 3 6 9 3 9 3 6 9 3 6 9 5 4
. 4 . . 6 . . 2 . . 6 . . 2 . . 4 . 5 2 . 7 4 . 7 6 .
. 5 6 . 3 4 . 7 6 . 3 2 . 7 4 . 5 2 4 . 7 2 . 5 2 . 3

Dan



Date Subject Author
3/24/11
Read One Through Nine, With Eight Missing, And Two Ones
Leroy Quet
3/24/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Leroy Quet
3/24/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Ilan Mayer
3/24/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Dan Hoey
3/24/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Leroy Quet
3/24/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Dan Hoey
3/25/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Leroy Quet
3/26/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Leroy Quet
3/28/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Leroy Quet
3/28/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
quasi
3/28/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Mark Brader
3/29/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
quasi
3/28/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
bulland@gmail.com
3/29/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
The Qurqirish Dragon
3/25/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
James Van Buskirk
3/29/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Dan Hoey
3/29/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
James Van Buskirk
3/30/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Dan Hoey
3/31/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
James Van Buskirk
3/31/11
Read Re: One Through Nine, With Eight Missing, And Two Ones
Dan Hoey

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.