I have a number n

I increase n. I now have a new number n+1

I change my mind and decrease n: I now have a new number n-1

I change my mind again and increase. I am now back to n+1

No matter what I do along the above lines by increasing and decreasing, I can't get back to n.

What am I doing?


The answer may be nearer than you think


1 Answer 1


Is it:

The StackExchange vote system? If you upvote someone, he goes from 0 to 1, but if you decide to downvote him afterwards, it'll get to -1, and we can never go back to 0.

  • 4
    $\begingroup$ I hope not, because you can in fact undo that. (Just click in the same place again.) $\endgroup$
    – Gareth McCaughan
    Mar 18, 2019 at 11:21
  • 1
    $\begingroup$ @ Gareth McCaughan - Yes but I clearly said, "No matter what I do along the above lines". That means by performing the same set of operations. $\endgroup$ Mar 18, 2019 at 12:29
  • $\begingroup$ @chaslyfromUK sorry, I actually didn't think this would be the answer. It's too late to edit it but I can just delete it instead. $\endgroup$
    – hexomino
    Mar 18, 2019 at 12:37
  • $\begingroup$ @chaslyfromUK without your clue i don't think that I could have find the answer so quickly ;) $\endgroup$ Mar 18, 2019 at 13:06
  • $\begingroup$ @chaslyfromUK Does increasing twice in a row count as performing the same set of operations to return to $n$? $\endgroup$
    – noedne
    Mar 18, 2019 at 14:16

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