Category Archives: puzzles

Friday puzzle: Nullarbor Plain

Last week’s puzzle was to list all the countries that begin and end with “A”. It is surprisingly difficult. Austria, Australia…hmm. Ah yes, Albania. I gave you Antigua & Barbuda (in the Caribbean). A stage of the Tour de France … Continue reading

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Friday puzzle: countries

Last week was the monkey puzzle. Monkeys go along a corridor shutting doors that are open and opening ones that are shut. It doesn’t take too much thought about this to realize that the doors left open will be those … Continue reading

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Friday puzzle: monkeys

It’s Friday on Thursday this week since Friday is a holiday for many people. Last week’s puzzle was to determine the largest order of McNuggets that McDonalds cannot make up using their portion sizes of 6, 9 and 20. It’s … Continue reading

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Friday puzzle: McNuggets

Last week’s puzzle was to calculate the resistance between opposite corners of a cube of identical resistors. Let’s assume they are all 1Ω since it doesn’t really matter. The key insight with this and many such problems is to find … Continue reading

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Friday puzzle: cube

Last week’s puzzle was the “two switch” puzzle. To solve it, the group of prisoners must identify one person, the counter. Ignore switch B, it is there just to give people something to toggle if they don’t want to toggle … Continue reading

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Friday puzzle: switches

By the way, I moderate comments on the puzzles, just to stop people posting the answer in the comments and so making it hard to avoid seeing accidentally if you want to try the puzzle yourself. So if you comment … Continue reading

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Friday puzzle: impossible

Last week’s puzzle was to calculate the volume remaining after a hole 6” long is drilled through a sphere. When I was a math nerd in high-school I actually knew how to do the triple integral in spherical polar coordinates … Continue reading

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Friday puzzle: sphere

Last week’s puzzle was about a man who went on a triangular walk and shoots a bear. The well-known solution is that the man must be at the North Pole (since the triangle returns him to his starting place) so … Continue reading

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Friday puzzle: bear

Last week’s puzzle was to continue the infinite series 110, 20, 12, 11, 10… The answer is that the subsequent terms are all 6. The series consists of the number 6 in binary, base 3, base 4 and so on. … Continue reading

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Friday puzzle: series

Friday is the day before the weekend, of course, so time for something less directly related to EDA, design, semiconductors and, well, work. In the UK, there is an expression about being POETS, which stands for “p*** off early tomorrow’s … Continue reading

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