User talk:Oscarlevin

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Revision as of 08:18, 12 October 2010 by Oscarlevin (talk | contribs)
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Solutions over multiple lines

I visited the site following the link in your comments on Richard Wiseman's most recent Friday Puzzle solution, and thought I'd see if I could contribute.

However, I can't contribute a solution because the wiki won't accept a solution that takes more than one line. For example, this doesn't work:

{{Solution | 
solution
over
multiple
lines
}}

Pretty much all solutions will require multiple lines, so this is a real problem. I assume a "solution" means an answer with working, whereas an "answer" is just the answer by itself.

Below is my solution to the 7 orbs puzzle, which I tried to contribute:

Let A = set of orbs for which there are 3 or more others the same colour.
Let B = set of orbs for which there are 1 or 2 others the same colour.
Let X = set of orbs for which there are no others the same colour.

Goal is to prove that some orb is in A.

Possible combinations:
(using the shorthand that A denotes an orb that's in A, etc)

A A A A A A A
A A A A A A X
A A A A A B B
A A A A A X X
A A A A B B B
A A A A B B X
A A A A X X X

Label the orbs 1, 2, 3, 4, 5, 6, 7 and test 1&2, 3&4, 5&6.

Comparing the results of testing those three pairs with the possible combinations, you can easily show that:

If two tested pairs glow the same colour, all members of those pairs are in A
If only one of the three tested pairs glows, members of that pair are in A
If two tested pairs glow different colours and the other doesn't glow, orb 7 is in A
If no tested pairs glow, orb 7 is in A.

In all cases, three tests suffice to prove that some orb is in A.

The only other thing required is to prove that two tests are not necessarily sufficient, which is trivial.

Is that the sort of thing you're looking for? Zerrakhi 12:16, 11 October 2010 (EDT)

Yes that is the sort of thing I'm looking for. I'll see if I can fix the multiple lines problem. Oscarlevin 15:06, 11 October 2010 (EDT)
So I can't seem to replicate your problem. Is it just that the lines are not breaking? Like this:
Solution

solution over multiple lines

Because that can be fixed will a line break between them, as in:
Solution

solution

over

multiple

lines

Or is there some other problem? Oscarlevin 15:25, 11 October 2010 (EDT)
The problem wasn't with your multiple lines, it was with the = sign. Templates allow you to have named parameters, which you assign with =. I don't know if there is a workaround for this. Oscarlevin 15:41, 11 October 2010 (EDT)
Ah. Never thought of that. I just tested in preview mode, and found that nowiki tags around the = sign seemed to work. I've written something up on the Editing Help page. Zerrakhi 19:27, 11 October 2010 (EDT)

No link in email

The email received upon registration, the one containing the words "open this link in your browser", does not actually contain any links or URLs to open! Zerrakhi 12:27, 11 October 2010 (EDT)

Did the email you get contain a bunch of <math></math> tags? I'm using an extension that switches dollar signs to math mode (ala LaTeX), and it has screwed up a lot of the system messages. I'll see if I can fix this too. Oscarlevin 15:06, 11 October 2010 (EDT)
Yes, that's right. Zerrakhi 19:27, 11 October 2010 (EDT)
This should be fixed now. Just testing a few things out. Test1 22:03, 11 October 2010 (EDT)

More questions

I'm wondering why only a few puzzles are in the needs solution category, and likewise for other similar categories. What's special about those puzzles in particular?

Because the 7 orbs puzzle is listed first on the front page, I assumed it was representative, and that all puzzles would have a hint, answer and solution in the same format. Now that I've seen that's not the case, I'm less sure about how I can contribute further. (Except by asking pointed questions, of course.) Zerrakhi 09:38, 12 October 2010 (EDT)

The only thing special about puzzles which have "needs ___" on them is that I happened to include that when I first put them up. Some puzzles were supplied before I had created those templates, and others after but I forgot to include the reminder. So for any puzzle you see on here that you think deserves a hint, answer or solution, feel free to provide one.
There are other things you can do, if you like. If you know of another puzzle, please add it. You can also improve current puzzles by giving variations, more references, links to similar puzzles, or notes on the mathematical content. In addition to being a collection of puzzles, I hope this wiki becomes a resource for math teachers. So any comments about how a particular puzzle relates to a mathematical concept are welcome. Finally, if you have any further ideas on how to improve the wiki, I'd be happy to hear them. Feedback is always good. Oscarlevin 10:18, 12 October 2010 (EDT)