How Do You Solve This Mysterious Number Puzzle?

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    Logic Puzzle
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Discussion Overview

The discussion revolves around a logic puzzle involving a sequence of equations that produce seemingly unrelated results. Participants explore the nature of the puzzle, potential solutions, and the underlying assumptions regarding the relationships between the numbers presented. The scope includes mathematical reasoning, logic, and the exploration of possible functions that could fit the given data.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants suggest that the answer to the puzzle could be "1," but the reasoning behind this is questioned and debated.
  • There is discussion about the nature of the function that could relate the inputs to the outputs, with some proposing that it could be a multivariate polynomial.
  • Others argue that the puzzle may not have a unique solution and could be interpreted in various ways depending on the assumptions made.
  • A participant mentions that the puzzle resembles those found in a puzzle book, indicating that it may require a mix of logic and general knowledge rather than strict mathematical proof.
  • Some participants express uncertainty about the restrictions on the function and whether it can yield any real number as an output.
  • There is a critique of the way the puzzle is posed, suggesting it should focus on uncovering hidden assumptions rather than seeking a single answer.
  • One participant notes that the problem is mathematically underdetermined, indicating that multiple interpretations and solutions may exist.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the nature of the solution or the assumptions underlying the puzzle. Multiple competing views remain regarding the interpretation of the problem and the potential for various solutions.

Contextual Notes

The discussion highlights limitations in the assumptions made about the function relating the inputs and outputs, as well as the ambiguity in the puzzle's requirements. The mathematical properties of the proposed functions are also under scrutiny, with references to historical mathematical problems indicating the complexity involved.

YoungPhysicist
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A logic puzzle I just found online:
$$
5+3+2 = 151022\\
9+2+4 = 183652\\
8+6+3 = 482466\\
5+4+5 = 202541\\
7+2+5 = ? $$
143547
The first two digits are the first two numbers multiplied.
The middle two digits are the first and last number multiplied.
The last two digits are the first two digits plus the middle two digits minus the second number.
Edit: The answer to the problem is not 14.
Please post how long did the problem take you to solve:wink:
 
Last edited:
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Young physicist said:
Edit: The answer is not 14.
Agreed, it did not take me 14 seconds to solve this.
 
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berkeman said:
Agreed, it did not take me 14 seconds to solve this.
How long did it take you?
 
1 is a correct answer, that takes about 0.65 s on average: 0.5 s to grasp the kind of question, 0.15 s average reaction time.
Difficult to say how long it took @berkeman to find the pun. This varies too wide across the species. E.g. I'm bad at this and it usually takes me several thoughts.

Now do you know, why 1 is a correct answer?
 
fresh_42 said:
1 is a correct answer, that takes about 0.65 s on average: 0.5 s to grasp the kind of question, 0.15 s average reaction time.
Difficult to say how long it took @berkeman to find the pun. This varies too wide across the species. E.g. I'm bad at this and it usually takes me several thoughts.

Now do you know, why 1 is a correct answer?
Maybe the pattern can’t “hold” like the number sequence? Every answer is possible.
 
Young physicist said:
Maybe the pattern can’t “hold” like the number sequence? Every answer is possible.
I don't understand the question, but your second sentence is correct.

a) We have a code of the type ##(p,q,r;N)## with natural numbers.
b) We also have the implicit assumption that there is a function ##N=f(p,q,r)##.
c) The question is therefore: Given ##4## points of the graph of the function, what is the function value at a fifth point?

Now how many functions are out there, which have at least these four points in common?
Even if we assume, that ##f(x_1,x_2,x_3)## is a multivariate polynomial, say ##f(x_1,x_2,x_3)= \sum_{n_1+n_2+n_3=m} a_{n_1n_2n_3}x_1^{n_1}x_2^{n_2}x_3^{n_3}## then how many functions of this type satisfy finitely many given conditions ##f(p,q,r)=N##, in our case five?

Have a look at ##f(x,y)=5x^3+2xy^2-10x^2y^3+3x-4y##:
https://www.wolframalpha.com/input/?i=f(x,y)=5x^3+2xy^2-10x^2y^3+3x-4y

Now imagine such a graph with some points fixed. How many such surfaces are still possible which contain those points? We even have an additional dimension, an arbitrary high degree for our multivariate polynomial, and this special form for ##f(x_1,x_2,x_3)## has already been a deliberate restriction. Imagine if we add all trigonometric functions, exponential function, roots of any degree or whatever.
 
fresh_42 said:
1 is a correct answer, that takes about 0.65 s on average: 0.5 s to grasp the kind of question, 0.15 s average reaction time.
Difficult to say how long it took @berkeman to find the pun. This varies too wide across the species. E.g. I'm bad at this and it usually takes me several thoughts.

Now do you know, why 1 is a correct answer?

This misses the point. This could be a code. In which case, breaking the code is to find a simple pattern to the numbers. Last year someone showed me a copy of the GCHQ puzzle book.

https://www.waterstones.com/book/the-gchq-puzzle-book/gchq/9780718185541

This is the sort of puzzle you'll find in there. These puzzles do not generally involve pure mathematical proofs, but a mixture of maths, logic, abduction and general knowledge.
 
PeroK said:
This misses the point.
No. It criticizes the way it is posed##{}^*)##: Find the answer! It should read: Find all hidden assumptions! Or if you like and suggested: Break the code!
To claim there is a unique answer might be o.k. on facebook, within a mathematical context it is not.

##{}^*)## This refers to the general way those questions are asked, not the specific one by the OP.

Edit: Alternatively the question would have to be a minimum problem: Find the shortest (including the reason) answer, in which case the measure must be named and the minimality must be proven. Or the requirement ##f\, : \,\mathbb{N}^3 \longrightarrow \mathbb{N}## should be made. But then uniqueness becomes a big problem without further conditions (I guess).
 
Last edited:
If you restrict f to be of no higher degree than bilinear in p,q, and r is it true that N can be any real number?
 
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Vanadium 50 said:
If you restrict f to be of no higher degree than bilinear in p,q, and r is it true that N can be any real number?
The supposed solution isn't linear in any variable, only affine linear. If we restrict the allowed powers of ##p,q,r## to be at most ##1##, then it depends on what ##p,q,r## are allowed to be. E.g. the answer is yes, if ##r \in \mathbb{R},## although it would not necessarily contain the four points. If we restrict ##f## on integers both on domain and codomain, then we quickly get a question like FLT, and that took about ##350## years and a very persistent genius to solve.
 
  • #11
Since we are talking more about the properties of such questions than giving the intended answers, I will close the thread.
It is a fun question, but mathematically underdetermined.
 
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