First, an important announcement. Last week I had an email from Psychology class 13B. Each week their fab teacher, Mrs Roo, encourages them to do the Friday Puzzle. However, Mrs Roo is leaving this week and so they wanted to say…..‘Goodbye Mrs Roo, we will miss you! Love from 13B’!

OK, to the puzzle. As ever, please do **NOT** post your answers, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.

How many squares are there on an 8 x 8 chessboard?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called **PUZZLED** and is available for the **Kindle** (UKhere and USA here) and on the **iBookstore** (UK here in the USA here). You can try 101 of the puzzles for free here.

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Have the way to figure it out, but am too lazy to do the work.

10 seconds using Google

It took me a few minutes to work out an algorithm for it.

Solved – easy, if I am right

They’re Pawns not Squires, so there are 16… Oh.. Squares not Squires..

I thought I had it, I just thought that’s easy.

I start scrolling and see “Do you make assumptions?”

Well played Richard, well played.

Are you from Class 13B?

and counting… got the answer, verfied by Google.

Wrong

I’m not a psychology professor, I was thinking more of the owner of this blog

and no, I don’t think it is relevant, you were clearly still eager to post a solution

I love a good non-sequitur, Anders

Keep ’em coming

I was just going to moan how you are clever enough to work out the answer but not clever enough to read the instructions of not posting the answer, but Richard has not put that bit in this week, so instead I wish you a very merry Christmas!

Got it, and if my clock works it took about 4 minutes, and yes, anonymous is wrong (and an idiot for trying to publish the answer)

and now it does, so a hex on you!

Rats. Anonymous is wrong. And I don’t know why; so some smartypants can tell us next week. Please don’t tell us before anyone else!!!

I was all pleased with myself for working it out. I was going to say that it took me 10 minutes. But now I won’t as I’ll look like an idiot for getting it wrong too! :D :D :D

And Anonymous: :( revealing your answer early.

Maybe the people saying (s)he’s wrong are wrong.

About a minute working it out, then realizing the pattern.

But looking at some of the other comments, I’m not so sure now…

In my wold a chess board has only black squares on a white background…. and there two diagonally adjacent squares make no new square…

so my answer would be the nubmer of the black fields in a chessboard…

(and as i assume that this is not the answer Mr. Wiseman had im mind, i do not feel like posting “the answer”)

In my world, the comments page is only black letters on a white background. The letters exist, but the page does not, and neither does your comment.

I find the fun of the puzzle is to figure it out yourself, and to read the comments afterwards, as even reading a comment saying “1 minute” makes me see the answer quicker – human nature and competition I guess. Still anonymous certainly fails for not following instructions! Anyway took a few minutes to figure out the method, and a few more to find some paper for the sums.

I agree, if you know the answer is quickly solvable, it becomes quickly solvable. Weird, but I think it’s because you search a simple solution space rather than fret over having to come up with some ingenious or fiendishly complicated piece of reasoning.

Got it, within 2 minutes, with a little help from my Excel.

Hint: it’s not 64…

Of course, we’re expected to do a sum and we’re dealing with squares…

Hints should be forbidden, as answers are.

can anyone please post the algorithm on Monday? I’d have to count, and I can’t be bothered…

New how to do it in seconds, worked it out on paper in some more seconds.

Took about 2 minutes. The answer has something to do with squares.

It’s been a while since there was a puzzle to commute by, thanks for another, I counted them on the train.

Condiments of the seasoning!

10 minutes

Less than a minute using a calculator for the final sum.

less then a minute

Pyramidal numbers.

It is been a long time since we had a decent puzzle. This one is so boring I can’t be bothered.

Once I figured out the structure of the answer, it took about a minute to calculate.

Not sure of the answer but I got 4 or 5 minutes

Last time we had this puzzle someone said it took them 3mins 24s – which was quite clever.

This is a very clever post, children, because 3′ 24″ is 204″ and 204 is the correct answer to the question.

When you are grown up you will be able to display your erudition in this way too, my little ones.

I did resolved it and it took me about 20 min.

About 40 seconds

SPOILER ALERT ………..The answer is quite a lot, well into double figure if not even more.

I almost get the impression that telling people to not reveal the answer makes them more eager to do so. Something for a psychology professor to investigate perhaps?

Would it help your psychoanalysis, Anders, to know I had no idea whatsoever of what the answer was when I posted my soi-disant “spoiler”

expanded puzzle, how many rectangles are there? Is there an answer as simple as for squares?

It didn’t specify vertical and horizontal sides, My first guess has more that three digits.

Just because they call it advanced doesn’t mean it is.

karol hubert rostworowski