Puzzling Stack Exchange is a question and answer site for those who create, solve, and study puzzles. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

This was on the entrance exam at our local university last year.
I still can't figure out the answer... enter image description here

share|improve this question

61

Because

Each number on the point is the sum of the squares of the numbers connecting to it.

share|improve this answer
    
Any intuition about whether there's a pattern to the inner numbers? – Parthian Shot Mar 7 at 19:25
1  
I doubt it. If anything, it seems to be made to be easy to figure out. Putting 5 or 6 next to 4 would give 41 or 52, neither of which is obviously a sum of squares. Although four of them being multiples of five might be an intentional red herring. – Lacklub Mar 7 at 19:30
    
@ParthianShot: (n+1) goes to n-th unfilled field clockwise – Erbureth Mar 8 at 13:35

$5^2 + 6^2 = 25+36$= $61$
Its just square and add

share|improve this answer
1  
The way I saw it was noticing that the bigger numbers in the "outer circle" seem to relate to the bigger number in the inner circle. Then I first noticed $5^2 + 1 = 26$, and seeing $4, 3$ and $25$ we have the famous pythagorean triple giving $4^2 + 3^2 = 5^2$ – Improve Mar 7 at 19:19
    
@Improve same case with me...coz I also saw the famous pythagorean triplet first...and later came to the conclusion.. :) – manshu Mar 7 at 19:22

Every number at the points is equal to the sum of the squares of the closest two numbers inside, so it's 25+36=61.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.