Math Is Fun Forum

Hmmm, I guess I should post my own answers (again, they aren't absolutely correct, only what I think).

Also, I apologize about not posting my own answers earlier, I forgot about the whole hiding answers, then I was searching the forum, because I couldn't figure out what the tag was.  Of course it would be the one thing I wasn't thinking...  [ hide ] and [ / hide ] (without the spaces).

In case anyone is interested in my answers for the actual phi brain puzzle in episode two (usually around 6:30 - 7:00 in the episode; you can find at http://www.crunchyroll.com/phi-brain/ep … ard-595519 where it is free and legal if you don't mind ads):

*EDIT* I added in my answers to the actual Phi Brain puzzle which I got made my puzzle from and added link where to find original puzzle.

Oh yeah, I realize 0/0 is also used for that purpose with convenience.  One of the things that actually gets me interested in these kinds of things is seeing how it may potentially be something other than what you think it is when you look more at it.  So in arithmetic, you learn 0 / 0 = (undefined), but then you begin to think, wait a second, what does that even mean exactly?  Why is it even undefined?  You learn more math later on, as you move on to algebra, calculus, um...set theory, also things you just simply study on your own, etc., which may provide you with even more reasoning for why it is like that.  But then, my friend tells me of something like this he concocts, and then, you just kind of laugh and say, this is seemingly quite simple and appears to make sense while also finding it quite clever (well I do anyway).  Even if it isn't true and doesn't work, I find the whole thing very interesting and still wonder if it does work with more explanation.  It still think on some level it could fit in, but there's so much I don't know, I'm not even able to say that with confidence.

Grantingriver, that is interesting!  I really do wonder if you are correct about that (the answer being A.), as that would lead to an actual answer.  I mean, it's online and lots of people troll.  But, that question did always stick with me because it felt too easy to say, yeah, I agree it's impossible because all answers are 25%.  What can you do where it has an answer?  Even if it were a troll, there must be some way to draw an answer out of it.  I can't so easily dismiss the question in my head, because why would they ask me such a question that seems too easily dismissed as impossible, and even call it impossible as if to tempt me that if I agree, I'm just one more person who doesn't bother to give it any additional thought.  Also, having a lot of personal experience working with different number bases, I'm inclined to agree with his reasoning.  Right now, I'm thinking that if that has an answer, I'd have to agree and say it is A. 71.

Lol, sorry about that.  I read everything, but since it took me longer to understand everything, so I guess I figured that out after you and forgot you said anything about that.

Lol, interesting how you specifically wanted to avoid what Relentless and I found .

Hmm, okay, I see you edited your original post, I got the information I needed.  Though I am curious about one thing.  Why did he have to take any non-birthday pages.  Since he lives forever, he could take birthday pages and only birthday pages for eternity.  I understand the part that he must eventually take all the pages, but with no time limit, that is actually irrelevant unless I'm mistaken.  I would argue that since he is living forever and can choose what pages (out of unlimited pages) to take out, he should be able to take arguably only birthday pages because he can theoretically always take all his non-birthday pages later (of course, that later will never happen).

Okay, just for fun.  Let's say that what my friend said is true (which I'm not saying it is).  In that example, v (or any variable), and not just any number would have to be equal to 0 / 0.  What you are trying to do is get to the answer 0 / 0.  As it stands, if you were to multiply 0 by any number, you would get 0.  Therefore, using that, 0 / 0 does not make 1, nor 2, nor 3.  It remains an undefined variable unless you were using it in some defined manner.

Now how can the variable possible be defined.  So I'll make up a problem to try to give an example.  So the problem would go something like this:  0÷0+b = a-1.  If b is 3, show that 0(a) = 0(4).
0÷0+b = a-1
0÷0+b+1 = a
0(0÷0+b+1) = 0(a)
0[(0÷0)+(+b+1)] = 0(a)
0(0÷0)+0(b+1) = 0(a)
0+0(b+1) = 0(a)
*0(b+1) = 0(a)

     filling in 3 for b....
0(3+1) = 0(a)
0(4) = 0(a)
0 = 0

Now after doing all that, my point arises with the specific variable being defined, while 0÷0 still existing.  0÷0 still however remains undefined in this way.  That's the first part of what I was talking about...

The second part...

Making this very simple, if 0/0 = v, and v = 3, then 0/0 = 3.  0/0 = v, but it also = 4, or 5, or 6.  Since v is now defined, v is just 1 of infinite things 0/0 may be.  Yet if you use an undefined variable, like in the example I gave where "a" never gets defined (but "v" does).  Even in step 2 where 0÷0+b+1 = "a", that's as much of a definition as you're going to get because you still can't determine what 0÷0 is, making a an even different undefined variable showing how this all may seem simple, but it can very quickly get more complicated.  So I repeat again, there's reason this remains undefined.  Comparing it to a variable is something interesting, but if you actually want to go deeper in understanding it, it will get more and more difficult as you advance.

I would also like to add that I made a bit of a mistake, saying "only 3 = 0/0, and not 2", like what I was saying above, is it's specific to the variable "v".  If 3 is defined as "v", then v ≠ 2, and 0/0 = um...let's say "w" which remains undefined, unless you define that as well, then you must use another variable as long as it remains undefined.

Anyway, let me make my case clear now, 0/0 ≠ v.  It was an interesting comparison, comparing the answer to a variable, but it just isn't as simple as that.  I am still interested in what people have to comment on it because I still find the comparison really interesting as it reminds me of something a kid would do.  But I want to make sure everyone understands I don't actually think this is how it works...

* *edit* I changed "v" to "b" because I noticed I put "v" by mistake....

Interesting, I'll do some investigating into this then.  Because I do believe there is a way to get it to work still.  Such as, as I stated earlier, applying the chat room to say only members only areas and such; someplace that guests would not have access to it.

That's what Relentless also pointed out...

It is an issue with how you are looking at it.  If I were to try to argue the case, I'd say it's a bit flawed.  1 ≠ 0/0, nor does 2.  v = 0/0, and it will remain undefined unless there's something else that will allow it to be defined.  In other words, v may = 1, v may = 2, but unless it is defined, you can't simply say it is 2.  However, if v = 0/0, and for some reason v were defined as 3 in this case.  Then only 3 = 0/0, and not 2.  It would have to be specific to that 0/0.  However, please don't try to look at it this way.  Anything divided by 0 is undefined or the like, and for reason.  I'm not trying to argue that 0 / 0 should equal v.  I only was pointing out something interesting that helps you look at 0 / 0 that I found interesting (which doesn't mean it is correct).

Yes, sorry, I understood most of that.  The issue I'm having is some smaller details mentioned which is causing me to get confused about the whole thing.  It is why I quoted both of them:

Those are the parts I'm having the most difficulty understanding.  However, you bring up now another question, which is related to trying to understand the first part I quoted (sorry about all the confusion, I'm only trying to understand this)...

So does that mean that by tearing a page out, it happens the day after?

Interesting point (it took me a little bit to realize what you were saying).  It is at least one of the issues calling it v.  But again, I never listed it saying it was correct, I just thought that such a simple thing like that was worth mentioning out of interest.

Unfortunately dividing any other number by 0 creates a lot more issues.  I've worked with it before with my friend.  1 / 0 can not equal v like 0 / 0 can.  That point I made only works with 0 / 0.  As you pointed out, if you divide 1 / 0, you can not reach a number.  There isn't a number in existence (that I'm aware of) that can answer that question.  Some may argue the answer is ∞.  But then comes an issue with using ∞ as a number, which it isn't (or at least not exactly in that way).  Plus there are issues to that.  If say 1 / 0 = ∞, what does 2 / 0 = ?  Does it also equal ∞, does it equal 2∞?  How do you even begin to make sense of it?  You can make sense of it, but I don't know anything in mathematics that will answer it except for maybe...1 / 0 = undefined (or something of that nature).  Probably already realized all this, but at least interesting to point out.

Okay, is that http://www.mathisfunforum.com/viewtopic.php?id=20534? Or is that a different one?  I was suggesting bringing back the big one to have a big one available, but I guess it doesn't matter if there is still one open.