What is the Next Number in this Series?

  • Thread starter Thread starter Aditya
  • Start date Start date
Click For Summary

Discussion Overview

The discussion centers around identifying the next number in a given series: 10, 4, 3, 11, 15. Participants explore various approaches to determine the next number, with a hint suggesting the solution is not math-related.

Discussion Character

  • Debate/contested
  • Exploratory
  • Mathematical reasoning

Main Points Raised

  • One participant suggests a pattern involving alternating increases and decreases in distance from a central number, proposing 14 as the answer.
  • Another participant argues that the reasoning is flawed, claiming the answer can be derived from the number of letters in the spelled-out numbers.
  • A different approach involves mathematical reasoning, where one participant sums pairs of numbers to arrive at a potential next number.
  • Multiple participants note that there are several independent rationales leading to the same answer of 14, but also mention other possible answers (1, 17, 12) based on polynomial fitting.
  • One participant asserts that the polynomial approach is not valid since the puzzle is not math-related, suggesting that the correct answer may not be among the provided options.
  • Some participants express skepticism about the validity of the patterns identified, emphasizing that a convincing solution should be simple and clearly intended.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correct answer or the validity of the various approaches. Multiple competing views remain, with some supporting the answer of 14 while others question the reasoning behind it.

Contextual Notes

Participants highlight that the puzzle is intended to be non-mathematical, which complicates the use of polynomial fitting as a justification for the answers proposed.

Who May Find This Useful

Individuals interested in pattern recognition, logic puzzles, or non-traditional problem-solving approaches may find this discussion engaging.

Aditya
Messages
8
Reaction score
0
Which number is next in this series:

10, 4, 3, 11, 15...?

a. 14
b. 1
c. 17
d.12


Hint: Not Math Related
 
Physics news on Phys.org
The pattern is this: number A, two numbers that are 1 in distance that decrease, one number 1 in distance from number A that increases, then two more numbers that are 1 in distance that decrease.

The answer is a, 14.
 
No, not really. Although the answer is correct, the reasoning behind it is incorrect. If you spell out each letter you can notice that for each number the number of letters increase by 1.
 
can it be 14?
 
lol..I got it in mathematical way. 10+11 = 21, 4+15 = 19 so 3+? = 17
 
Wow. Cool. 3 right answers, with 3 completely independent rationales for reaching it.
 
Correct answers are: a, b, c or d.

If I knew how to use lagrange to make polynomials to fit those points I'd prove it, too.
 
Its easier than that Alkatran:

The polynomial [itex]y = (x - 10)(x - 4)(x - 3)(x - 11)(x - 15)(x - 14)[/itex] has zeros 10, 4, 3, 11, 15, and 14. This justifies the answer a. 14.

The polynomial [itex]y = (x - 10)(x - 4)(x - 3)(x - 11)(x - 15)(x - 1)[/itex]has zeros 10, 4, 3, 11, 15, and 1. This justifies the answer b. 1.

The polynomial [itex]y = (x - 10)(x - 4)(x - 3)(x - 11)(x - 15)(x - 17)[/itex] has zeros 10, 4, 3, 11, 15, and 17. This justifies the answer c. 17.

The polynomial [itex]y = (x - 10)(x - 4)(x - 3)(x - 11)(x - 15)(x - 12)[/itex] has zeros 10, 4, 3, 11, 15, and 12. This justifies the answer d. 12.

However, the correct answer to the puzzle was not one of the choices. You see the polynomial [itex]y = (x - 10)(x - 4)(x - 3)(x - 11)(x - 15)(x - \pi)[/itex] has zeros 10, 4, 3, 11, 15, and [itex]\pi[/itex]. So there is no correct answer.
 
Last edited:
Aditya said:
Which number is next in this series:

10, 4, 3, 11, 15...?

a. 14
b. 1
c. 17
d.12

This is the only one that makes sense to me.
14
 
  • #10
Wow... It's amazing how many patterns and relationships you can find, and they are all valid. I got my answer the same way that z-component got his.
 
  • #11
I don't think anybody has a convincing stab at this puzzle (myself included). Solving a pattern requires that you find something that is obviously right. Just being able to construct something that fits the pattern isn't enough. It has to also be simple and clearly the intended answer. Only if the intended answer does not itself fit those criteria is the pattern flawed.
 
  • #12
Plus, aditya said this is NOT math-related. No polynomials allowed. That's not the real point of why the polynomial approach is not right, but it adds some extra irony.
 
  • #13
BicycleTree said:
I don't think anybody has a convincing stab at this puzzle (myself included). Solving a pattern requires that you find something that is obviously right. Just being able to construct something that fits the pattern isn't enough. It has to also be simple and clearly the intended answer. Only if the intended answer does not itself fit those criteria is the pattern flawed.

I agree. Finding a pattern may not mean that you've found the answer. I think this one was a pretty creative pattern.
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 9 ·
Replies
9
Views
1K
Replies
116
Views
9K
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 3 ·
Replies
3
Views
793
  • · Replies 19 ·
Replies
19
Views
4K