You gave up trying to get the recipes, and go home. You get on Puzzling.SE to find your friend has been recording all your attempts (and his elephant failures).

You also find when you try to log into Puzzling.SE You get redirected to a question called "Security to your account!"

The body goes like this:

You try to get on Puzzling.SE so you can answer puzzles but find that a hacker has set up a password system. You wait to listen to traffic to see how he lets people in.

While analyzing traffic packets (You little hacker!) you get the following responses:

"5" -> "Impossible"
"6" -> "Impossible"

Then some bright guy who's also analyzing traffic thinks he's got it.

"0" -> "Impossible"

His computer then shuts down forever.
Nobody else comes for a while so it's your turn now!
Your question is "Infinity". What's your answer? Also, what was the correct answer to 0? Why?

To get it you know you have to answer the question. What is the answer?


What is and what can't is elementary.

Let it be known there are inverse operations!

You are in the basic math division.


"7" -> "Impossible"

"8"-> "Impossible"

  • $\begingroup$ Can you maybe give an example of a correct, different answer? $\endgroup$
    – Ry-
    Nov 13, 2014 at 18:43
  • $\begingroup$ @mini If no one gets it I will as a hint. $\endgroup$
    – warspyking
    Nov 13, 2014 at 18:46
  • $\begingroup$ In my opinion, this kind of puzzle is more fun if I have more data to think about. With only 3 or 4 data points there are bound to be simple answers that fit the data but that you won't accept. $\endgroup$
    – Lopsy
    Nov 13, 2014 at 21:13
  • 1
    $\begingroup$ Based off of the information, a correct answer is "Given a number n, the answer is n/(n-n)." I feel like this is incorrect (hopefully it is), yet it fits every single requirement. $\endgroup$
    – mdc32
    Nov 14, 2014 at 1:21
  • 1
    $\begingroup$ could also be sqrt(-x), only allows negative numbers and 0 $\endgroup$
    – Falco
    Nov 14, 2014 at 12:55

4 Answers 4


I think it is

0=0 Infinity=Impossible/Undefined


Arcsin 0=0 and arcsin infinity is undefined. Arcsin's inverse is sin.

  • $\begingroup$ Sorry, if it's possible there IS a number response. $\endgroup$
    – warspyking
    Nov 13, 2014 at 20:53
  • $\begingroup$ Can you add a hint? $\endgroup$ Nov 13, 2014 at 20:59
  • $\begingroup$ For every wrong answer I will add a new hint. $\endgroup$
    – warspyking
    Nov 13, 2014 at 21:12
  • $\begingroup$ @warspyking I changed my answer $\endgroup$ Nov 13, 2014 at 22:40
  • 1
    $\begingroup$ could be the reverse of any function which doesn't result in 5-8 as outputs but includes 0 (for example all functions which output 0-1, sin, cos, or -x^2) $\endgroup$
    – Falco
    Nov 14, 2014 at 12:54

I've solved it.

The correct response is always "impossible".

The computer shut down because of a coincidental hardware failure and the correct answer to 0 is thus "impossible".

I think my answer fits every case so far.


The solution is:



Five and Six can have opposites, but 0 can't.

  • $\begingroup$ This makes no sense. Your because does not even describe the solution. $\endgroup$ Nov 13, 2014 at 21:23

The question is:

Can you determine the image of this number if we consider an arbitrary 1-1 function on the set of integer numbers?

And the answers are:

0 -> 0, infinity -> "impossible".

Of course, this won't be the right answer, but this one sounds good to me. :-)

Previous attempt

The question is:

What does the number divided 0 times equals to?

The answers are:

"0" -> 1, "infinity" -> "Impossible". I'm not that sure about the second answer; the first should work with every number, not only "1".

  • $\begingroup$ Ex: 0 divided by 0 is an intermediate state. 1 divided by 0 is also an intermediate state, or infinity. Id this is true, the question makes no sense. $\endgroup$ Nov 13, 2014 at 21:29
  • $\begingroup$ Sorry, I can't understand what did you mean, can you explain me better? It'd be very appreciated. $\endgroup$
    – user1962
    Nov 13, 2014 at 21:36
  • $\begingroup$ Zero divided does not equal 1. 0x9=0 so shouldn't, 0 divided by 0 return 9? Or 8? Etc. $\endgroup$ Nov 13, 2014 at 21:38
  • $\begingroup$ I specified it. However, now I'll try to think about a plausible answer. $\endgroup$
    – user1962
    Nov 13, 2014 at 21:44

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