I am thinking of one thing.

It is either an ellipse (shape),

Or, it is the letter O

Or, it is the number 0

You can ask me one question and guess what the thing is.

I can only answer No,or sometime or always.

So what is it?

  • $\begingroup$ I've closed this as a duplicate because it's easy to translate questions from the linked puzzle into questions here and vice versa. $\endgroup$
    – Deusovi
    Apr 18, 2017 at 20:54
  • $\begingroup$ Why is this a duplicate? It does not concern 1,2 or 3? Only O,0 and ellipse $\endgroup$
    – DrD
    Apr 19, 2017 at 12:24
  • $\begingroup$ @DeepakMahulikar:  Read the comment immediately above yours. $\endgroup$ Apr 19, 2017 at 17:42
  • $\begingroup$ More broadly: Guessing among three possibilities with a single question $\endgroup$ Apr 19, 2017 at 17:44
  • $\begingroup$ @Deusovi. Isn't this just another puzzle of the same type? I can't see how you can use the questions from the linked puzzle here. This question is comparing a shape, a letter and a number so a purely mathematical question is not possible. $\endgroup$
    – Wolff
    Apr 21, 2017 at 16:21

2 Answers 2


I ask you -

Can you find it in the upper right corner of the obverse face of a US $1 bill?
enter image description here

The text always contains an O (letter)
The serial number sometimes contains a 0 (digit)
That part of a dollar never contains an ellipse.

Having said that, I suspect this question is too broad ... we'll probably see plenty of good answers.

  • $\begingroup$ Aren't Os ellipses and therefore the answer for ellipse would be "yes"? $\endgroup$ Apr 18, 2017 at 20:54
  • $\begingroup$ @JonathanAllan Then the question devolves to "Is it an ellipse, an ellipse, or a zero?" at best, or "Is it an ellipse, an ellipse, or an ellipse?" at worst; allowing them to be considered equivalent breaks the question entirely. $\endgroup$
    – Rubio
    Apr 18, 2017 at 21:05
  • $\begingroup$ Not necessarily, it just means we cannot use that precise nature to make our decision (and this possibly means it is nowhere near as broad as the 1,2,3 question). $\endgroup$ Apr 18, 2017 at 21:10

Can you rotate it ninety degrees without altering it?


You can always rotate the letter O, never rotate the number 0, and sometimes rotate an ellipse (because all circles are also ellipses).

  • $\begingroup$ Is number 0 always an Oval? In all Fonts? $\endgroup$
    – DrD
    Apr 19, 2017 at 12:52
  • $\begingroup$ This is not correct for the letter O — it is usually not a perfect circle. $\endgroup$ Apr 19, 2017 at 17:40

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