Guessing among 3 possibilities with a single question - can this be done with letters as well as numbers?

This is an open question to all.

I have seen a few " I am thinking of a number/s-- can you guess by asking one question to which I can only answer Yes, No or may be" puzzles which are interesting from logic perspective.

If not can one design a hard puzzle ( I am thinking of letters L,M or N just as an example) and have a defined solution?

If this type of puzzle already exists then I am sorry for this question. I could not find it.

• "I am thinking of one letter (a-z). How many question you need - which I can only answer Yes, No or may be? Also write those question." Like that? Or something that can't really be used on numbers, like shape or meaning or voiced/voiceless… Apr 7 '17 at 14:08
• The universe is based on numbers, so anything that can be done with numbers can also be done with anything else by reducing it to numbers. </mathematician> Apr 7 '17 at 14:22
• Recommend not including "maybe" in your list of possible answers. You could simply say "maybe" to everything, giving the guesser no information. Apr 7 '17 at 14:58
• @IanMacDonald "Maybe" as in "I'm not sure" or "It doesn't have a clear answer". Apr 7 '17 at 20:44

You can ask a question based on the shape of the possible letters (like @rand al'thor's answer), their alphabetical order (if it can be done for numbers, this will also work for letters), the letters in real or fictional people's names or other traits associated with the letters in question.

For the letters L, M, N, it can certainly be done. Inspired by this answer:

If you toss one coin for every straight line of the letter, and then remove one of those coins, will you still have two coins the same?

Of course, the answer will be:

YES for M (four lines), NO for L (two lines), and MAYBE for N (three lines).

A more imaginative (and letter-specific) solution:

Does the letter have an axis of reflectional symmetry?

The answer to this will be:

YES for M (vertical symmetry), NO for N (flipping it would turn it into a Russian И), and MAYBE for L (it may or may not have a diagonal axis of symmetry, depending on exactly how it's drawn and whether the two legs are the same length).

• True rand al'thor. can we make it really hard? what letters could do that
– DrD
Apr 7 '17 at 13:41
• Wouldn't "N" have a diagonal axis of symmetry? Apr 7 '17 at 14:40
• @dcfyj Nope. Which diagonal? It has rotational symmetry, not reflectional. Apr 7 '17 at 14:42
• Right, For some reason my brain goes to mush on the diagonals... Apr 7 '17 at 14:43

Let an alphabet A have N letters denoted as A={L1,L2,L3.....,LN}

One can choose 3 different letters from this subset s1,s2,s3 ∈ A

Let S a subset of N where S is a subset that contains s1, but doesn't contain s2 and may have several other letters.

So, the question should be:

Note: I think one can easily paraphrase this into 1 sentence question which includes above definition and it can actually solve all possible letter/number choices.

I'm sure there is a valid general solution:

Consider the two sets {X, Y} and {X}. If I choose a set at random, will it contain the letter you think of?

If I cannot reference the letters, then here would be the strategy to generate a solution:

Pick two letters and find in each a property which differs it from the others.

Or,

Pick two letters that share a similarity, then find a difference between the two.

So for example, À, Á, Â can be separated with this question:

I flip a coin and choose a random property. If heads the property is "The thing on top is drawn with two lines". If tails the property is "If downwards gravity is activated, the thing on top either falls to the right to hit the ground or becomes a hat and stays on". If I flip the coin, does your letter satisfy the represented property?

Consider a question that can be asked such that when asked to you, you will answer "Yes" if you think of X, "No" if you think of Y, and "Maybe" if you think of Z. If I asked this question to you, what will you answer?

For L, M and N,

If you append the letters "ax", do you get a standard English word?

Yes → L. "lax" is a word.

No → N. "nax" is not a word.

Maybe → M.  It depends on how accepting you are of English words.  Some dictionaries say "max" is slang, informal, or an abbreviation.

It worked so that I mapped “No” and “Maybe” to their initials (No → N and Maybe → M), and, of course, YL under ROT13.  And I wasn’t even trying to do that!

Suppose I asked you separate the letters into two groups, L is in the first group, N is the second group, and M will go either into the first or second group based on the result of a coin toss, then would the letter you're thinking of be in the first group?