which letter completes this puzzle?

[mg1]

l p v

r j b

x d ?

[Robert G]

What a stinker this is! Are you able to give any other information, or the context in which this puzzle was set?

[Clayhead]

Yes, what a stinker. Is it just a coincidence that they are ALL even-numbered letters of the alphabet? (L=12, P=16, V=22 etc.)

[mg1]

The question is in a charity quiz. The only other clue perhaps is that the letters are contained in individual shapes like 50p pieces - it's driven me nuts for days!!

[pquinlan]

I'm hooked to this puzzle now so can you please elaborate on last comment. Is it the letter j at the centre of one 50p shape, with other letters at corners? If not, please explain. Thanks in advance.

[mg1]

Sorry just looked at a 50p and it has 7 sides so that is wrong!

The letters are capital letters each contained in an octagon (ie 8 sided shape). Each letter is in the middle of each shape. Sorry for any confusion - i don't know if the shape has any relevance!

[Dustybun]

are your shapes completely separate or are they all joined together in a honeycomb effect?

[Robert G]

Unless we're all missing something pretty obvious - and I've been thinking laterally about this puzzle for far too long now (!) - perhaps the answer is the letter i, or rather, I (ie. capital i) - inside an octagon, of course!

Has anyone else come up with this as a possible answer? In my reasoning, to have done so would have required the penultimate step to have been to come up with 444.

Is anyone with me on this?

[mg1]

I think I have the answer - and it has nothing to do with the shapes - I believe the answer is H based on the fact that there are 5 letters between each letter if you put the alphabet in a circle and then go in the order of

l > r > x > d> j > p > v > b > and therefore leave a gap of 5 and it gives you h.

Very tenuous but I can find anything better!

[pquinlan]

Not tenuous at all, mg1, surely the right answer. I wasn't a million miles (in fact got H too) but failed to make the link from X to D and P to V. I was going down the columns with repeated increments. Mine was tenuous but you have done it, well done.

[Robert G]

That is ingenious, mg1. Congratulations! I might put my money on that one, although why should we follow the letters in that particular sequence, and not in some other sequence? Intriguing.

My possible solution, given a few minutes before yours, requires one to think in terms of texting on a mobile phone, the purpose of the octagons being to indicate keys:

Texting the letters given in the grid would require the following keystrokes:

55 7 888

777 5 22

99 3 ?

In searching for some pattern within these keystrokes, which must be set out in the same three rows of three, I reckoned that the unknown would have to be 444, which produces the letter 'I'.

The pattern? I deduced it as a combination of two simultaneous considerations:

Firstly, the numeral keys which have to be hit.

Secondly, the number of times they have to be hit.

Thus, firstly, we have:

5 7 8

7 5 2

9 3 ?

Working down the columns we see a possible pattern of:
Add 2, add 2 ... Deduct 2, deduct 2 ... Add2, add ? ...

Remember, of course, that on the phone keypad no letters attach to the no. 1 key or the no. 0 key, so going up one from 8 takes you to 9, and going up one from 9 takes you to 2.

Applying this would give ? as 4.

And, secondly (the number of times the keys have to be hit), we have:

2 1 3

3 1 2

2 1 ?

suggesting that the unknown could be 3, which would conform to a predictable numeric matrix.

Thus the numerical answer is three fours, ie 444, which, if hit on the phone keypad, produces the letter I

Quite simple, really!

[mg1]

well it took me a while to get my head round it and I really like the idea of the mobile phone.

However i think you have an error on your last bit about keystrokes and it should be

313,

312

21?

which could tenuously be that you add them up acrossways so it would be 7, 6 and to make up a 5 it would have to be the number 3 which would make it an H instead of an i.

which makes me happy cos it still comes to the same answer!!

[Robert G]

Ah! Yes, I see that you're right. I thought it was too good (or too obscure) to be true! So, yes, I would have to say 'H', too, except that I remain to be convinced about the purpose of the octagons in the question. I explored the layout of the keys on a qwerty (and other) keyboards but got nowhere with that. I cannot think of any practical use or applications of the octagon other than as a decorative apprearance for floor tiles, mozaics and columns! I'll put that as a new question within this topic, I think. Watch that space!

[pquinlan]

I feel that if the octagons are touching, it kind of indicates (a la blockbusters quiz show grid) that you can go in any direction you want. And down, up and down again isn't very obscure. Have nice weekend all.