Our little experiment was fun and interesting. It was a kind of a wisdom of the crowds thing, and examined the accuracy of the mean of people’s guesses. The average of the group was 44.58%. At 10 p.m. last night 38.30% of people had chosen BLUE, so the group was reasonably accurate. Stephen Motson was closest with 38.34% (email me and I will get a book to you).
I hope that you enjoyed it and thanks for taking part. So, to the Friday puzzle….
You are given eight coins and told that one of them is counterfeit. The counterfeit one is slightly heavier than the other seven. Otherwise, the coins look identical. Using a simple balance scale, how can you determine which coin is counterfeit using the scale only twice?
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.
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.