# What is the value of ⍰?

This is a question that I have been unable to figure out an answer to. Moreover I can't figure out what it relates to. It was given on a programming proficiency test.

the question mark symbol appears to be: U+2370 APL FUNCTIONAL SYMBOL QUAD QUESTION

Here is the question:

What is the value of ⍰ ?

⍰ + ⍰ = 10;
⍰ + ⍰ = 6;
⍰ + ⍰ = 5;

a. 6
b. 9
c. 7
d. 8
e. 1

• Isn't the U+2370 character drawn as a placeholder, instead of something else (e.g. an image or a TeX formula)? This might happen for example if the text rendering/displaying software encountered an error while trying to draw them. – trolley813 Jul 14 '20 at 5:46
• @trolley813 Nope, that's U+FFFD, �. The APL symbol doesn't have those semantics. I'm guessing the question setter just looked for a boxed question mark symbol. – Deusovi Jul 14 '20 at 5:47
• – Adám Jul 14 '20 at 11:32
• If it's a programming question, then what language has a single = assignment and no lvaues? If it's logic, why the ; at the end of each line? – Ken Y-N Jul 14 '20 at 12:07
• Is this.....javascript? – Tejas Kale Jul 15 '20 at 7:26

I have a theory: I think that the original puzzle looked like that:

What is the value of � ? � + � = 10; � + � = 6; � + � = 5; a. 6 b. 9 c. 7 d. 8 e. 1

� is the unicode replacement character, which was shown because the original symbols (some emoji?) could not be displayed (see Mojibake). So, what were the original symbols? We don't know, but we can try to make the puzzle solvable by substituting them:

What is the value of 😍 ? 🐟 + 😍 = 10; 🍎 + 🍎 = 6; 🍎 + 🐟 = 5; a. 6 b. 9 c. 7 d. 8 e. 1

Note that this is not the only solution, another one would be, for example,

What is the value of 😍 ? 🐟 + 🐟 = 10; 🐟 + 😍 = 6; 😍 + 🍎 = 5;

(yielding a different solution), but that one is boring, because the third equation is not required.

• +1: this definitely seems like the most likely explanation. (Also, welcome to Puzzling!) – Deusovi Jul 14 '20 at 12:06

This is probably a bit of a stretch, but maybe

e. 1

Reasoning:

I noticed that the ⍰ in the question is completely identical to the first ⍰ in each equation, but not the second one. This could just be the way it shows up and irrelevant to the problem, but it could also mean that the value of ⍰ only pertains to the completely identical ⍰s. If so, and if the second ⍰s must represent positive numbers, than the answer must be 1 because it is the only option with a lesser value than all the sums of the equations.

Also:

Even if all the ⍰s mean the same thing, I still might lean towards 1; 1 + 1 = 10 in binary, and the word "one" has 3 letters and 3 + 3 = 6. I don't see a good way to get 5 (1 is the 5th option but that doesn't seem like a reason that quite fits this puzzle.)

My response:

-4 + _

Explanation:

Consider ⍰ as a missing part of the equation,
in this case, when replaced, we get: -4 + _ + -4 + _ = 10
and we can now replace spaces with numbers from the condition

And from the higher ground we see:

     9        9
-4 + _ + -4 + _ = 10

7        7
-4 + _ + -4 + _ = 6

7        6
-4 + _ + -4 + _ = 5