Comments on: Problem Ten: The Fifteen Game http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/ Exploration, Calculation, Observation: Brain Teasers and Puzzles Wed, 07 Jan 2009 23:37:36 +0000 http://wordpress.org/?v=2.3.2 By: Percy http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-59 Percy Fri, 29 Sep 2006 00:17:05 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-59 Oh darn, I was so mistaken. I thought you individually had to get 15. Oh darn, I was so mistaken. I thought you individually had to get 15.

]]> By: tony http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-57 tony Fri, 29 Sep 2006 00:03:48 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-57 ok you guys pretty much got the answer but here's the really amazing thing to notice <spoiler> if you write down a magic square with numbers 1 thru 9 (i.e. every row, column, diagnal sums to 15) you'll get something like 4|9|2 ----- 3|5|7 ----- 8|1|6 Now the game is just like tic-tac-toe! That's why you should choose 5 first, because in this game choosing 5 is like getting the middle square in tic-tac-toe! </spoiler> ok you guys pretty much got the answer but here’s the really amazing thing to notice

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]]> By: Sarah & Heather http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-53 Sarah & Heather Thu, 28 Sep 2006 21:17:47 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-53 haha if the other guy picks 6, you pick 4 and then you win haha if the other guy picks 6, you pick 4
and then you win

]]> By: Percy http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-46 Percy Thu, 28 Sep 2006 16:20:23 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-46 Yeah, what if: You pick 5 The other guy picks 6 You pick 9 (to prevent the other guy from winning) The other guy picks 1 Now you're at 14, and the other guy's taken 1, so you're forced to go over 15. :( Yeah, what if:
You pick 5
The other guy picks 6
You pick 9 (to prevent the other guy from winning)
The other guy picks 1
Now you’re at 14, and the other guy’s taken 1, so you’re forced to go over 15. :(

]]> By: tony http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-45 tony Thu, 28 Sep 2006 15:31:43 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-45 I think you're close, but they could still possibly lose. There's a somewhat more ingenious solution. I think you’re close, but they could still possibly lose. There’s a somewhat more ingenious solution.

]]> By: Sarah & Heather http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-43 Sarah & Heather Thu, 28 Sep 2006 08:28:26 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-43 You go first, and pick up the 5. That way, no matter what they pick up, they can't make 15, but on your 3rd try, you can always make 15. You go first, and pick up the 5. That way, no matter what they pick up, they can’t make 15, but on your 3rd try, you can always make 15.

]]> By: tony http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-34 tony Thu, 28 Sep 2006 05:28:53 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-34 you lose you lose

]]> By: Percy http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-33 Percy Thu, 28 Sep 2006 05:15:21 +0000 http://www.tenproblems.com/20060927/problem-ten-the-fifteen-game/#comment-33 What happens if you go over 15? What happens if you go over 15?

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