This triangle is constructed from 10 coins.  What is the smallest number of coins that need to be moved to make the triangle point downwards?

As ever, please do NOT post your answers, but do say whether you think you have solved it and how long it took.  Solution on Monday.

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

71 comments

    1. I didn’t even finish the question 😦 very old puzzle that I have seen many times before.

    1. Read it again. The problem asks for the smallest number. That means that there is only one solution.

    2. There is only one solution, however what that is depends on how you interpret Richards question…

  1. Well, I think I-ve done it, but there may be a better answer, I just haven-t found it.

    Anyway, depending on how you look at it, the triangle could already be pointing downwards left or downwards right.

  2. but it already points downwarts.. in a rightish downwards direction and in leftish downward direction. …

    If you want it to point straigth down, … also possible, 3 seconds..
    without moving the upper and lower boundaries of the triangle an additional coin is required to be moved..

  3. sorry, have anohter (presumably incorrect solution).. after a few minutes.. definitivly including the minimum of coins to be moved…

  4. See, I think I’ve done it and it was far too easy so no doubt on Monday the answer will be something like ‘π x happiness’

    Oh how Mondays make me feel stupid.

  5. It took me about a minute to see the core pattern. I will check in on Monday to see if I got the correct answer.

  6. Isn’t it already pointing downwards? If you assume that one of the bottom corners of the triangle is the point. 5 seconds.

  7. If you are able to see the shape not as a triangle, but a composite of two items (one which will remain unchanged) the answer jumps out at you.

  8. Ah. I got one answer in about 20 secs, but then spent another minute seeing if I could find a better one. I believe I have the right answer now. Can’t see a better solution

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