Hello guzzlers.
Today’s puzzle originally appeared in the Christmas supplement of The Weekly Dispatch in 1896. It was devised by the magnificent Henry Ernest Dudeney, Britain’s greatest inventor of mathematical puzzles, who helped turn the late 19th century into a golden age for the field.
The Twelve Mince Pies
Below is an illustration of twelve mince pies placed on a table. There are six straight rows - each indicated by a dotted line - with four pies in each row.
The puzzle is to move four of the pies to new positions so that there are seven straight rows with four pies per row.
Which four would you move and where would you place them?
I’d prefer it if you used mince pies to solve this, but you might find it more convenient to use 12 coins. I’d mark the starting positions of the mince pies/coins on a piece of paper, otherwise it will get really confusing.
In fact, if you want to tweet your solution USING REAL MINCE PIES with the hashtag #MondayPuzzle Ill run a gallery of solutions later.
Henry Ernest Dudeney supplied puzzles to many British newspapers and magazines from the late 19th century to his death in 1930. He devised many classics and was instrumental in consolidating the genre.
The mince pie puzzle is a “points and lines” or “tree-planting” problem, so called since the most famous example (which Dudeney credits to Isaac Newton) is the challenge to plant nine trees in ten rows of three trees each. If you haven’t heard that one before, I’ll leave it as a stocking filler...
I’ll be back later today with the solution. (The solution is now up).
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I post a puzzle here on a Monday every two weeks.
My most recent book is the mathematical adult colouring book Snowflake Seashell Star. (In the US its title is Patterns of the Universe.)
You can check me out on Twitter, Facebook, Google+ and my personal website.
And if know of any great puzzles that you would like me to set here, get in touch.
