puzzle.

johnholden1 · 2012-04-26 08:50:43

I've been absolutely confounded by this problem for a couple of days now, its probably something really stupid, but the worst thing about it, it is a problem that was meant for 12 year olds!!

John E. Franklin · 2012-05-19 12:13:58

I think the answer is 8 or 9 in missing corner. My reasoning is that the difference between adjacent sides form 2 and 3 and
2 times 3 is 6 in the middle. Now if you always difference (subtract) adjacent sides and make positive and choose the
smallest and greatest ones and multiply them you get the middle, but also if the number is a perfect square such as
4, 9, 16, 25, 36, 49, 64, 81 , 100, etc, then you write down the square root in the middle. That's the best I could do for you.

anonimnystefy · 2012-05-19 20:53:16

What about the second square?

Bob · 2012-05-19 23:00:40

Here's an answer but I don't think you'll like it.

Let a = -2072/643

b = 1650/643

c = -209/643

d = 864/643

Then the centre number is generated by the formula

aW + bX + cY + dZ where W is the top left hand number, and the rest follow round clockwise from there.

That makes the missing number approximately -14.8421052631579

Hummmmmmm! I wonder if that was what was intended.

Bob

anonimnystefy · 2012-05-19 23:44:40

That is a nice answer,but it seems to me that the answer is supposed to be an integer.

Bob · 2012-05-20 01:11:14

Well yes, they usually are. But it doesn't actually say that.

I gave up on squaring and rooting as you wouldn't get those numbers, ditto division.

Even multiplying can only be done with care or the calculations get quickly too big.

So I tried every variation of adding and subtracting without success.

Then I thought of making linear combinations.

I juggled a few possibilities and then realised, with 4 equations and 4 unknowns, a solution must be in there.

So I solved and that's what I got.

I'm sure that is not the intended answer, but the setter would have to agree, it works!

Bob

John E. Franklin · 2012-05-20 22:24:28

In my post#2 method, if you do 8 minus 8 and get zero, you call it 8. There is no number below one in the rules.

anonimnystefy · 2012-05-20 22:42:31

But the third doesn't work then, either.

John E. Franklin · 2012-05-21 09:27:41

No the third is a perfect square 9, so you square root it, that's my rule.

anonimnystefy · 2012-05-21 09:32:06

I am gettin (5-4)*(13-7) to be 6.

??

EDIT:I have read your post again. But I don't see how it applies to square no. 4.

Last edited by anonimnystefy (2012-05-21 10:02:55)

John E. Franklin · 2012-05-21 10:07:40

13 - 4= 9 that is the maximum one, so use the max and the min of 1 and 9 max and square root it to 3.

anonimnystefy · 2012-05-21 10:18:26

Yes,Ibsaw that later. Look at the edit in my post.

John E. Franklin · 2012-05-21 10:47:53

Okay, 3 x 9 = 27 and 27 is a cube, not a square, so you just leave 27 for that one.
3 is the min difference and 9 is the max difference.

anonimnystefy · 2012-05-21 10:53:12

Oh,I see,adjacent. So what is.you answer for the fifth one?

John E. Franklin · 2012-05-23 08:53:33

Without looking back to post#1, my post#2 says 8 or 9 would work with these silly restraints.

anonimnystefy · 2012-05-23 09:55:37

But that cannot be true then! The puzzle should have one solution.

Math Is Fun Forum

#1 2012-04-26 08:50:43

puzzle.

#2 2012-05-19 12:13:58

Re: puzzle.

#3 2012-05-19 20:53:16

Re: puzzle.

#4 2012-05-19 23:00:40

Re: puzzle.

#5 2012-05-19 23:44:40

Re: puzzle.

#6 2012-05-20 01:11:14

Re: puzzle.

#7 2012-05-20 22:24:28

Re: puzzle.

#8 2012-05-20 22:42:31

Re: puzzle.

#9 2012-05-21 09:27:41

Re: puzzle.

#10 2012-05-21 09:32:06

Re: puzzle.

#11 2012-05-21 10:07:40

Re: puzzle.

#12 2012-05-21 10:18:26

Re: puzzle.

#13 2012-05-21 10:47:53

Re: puzzle.

#14 2012-05-21 10:53:12

Re: puzzle.

#15 2012-05-23 08:53:33

Re: puzzle.

#16 2012-05-23 09:55:37

Re: puzzle.

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