Enigma 184: Product sum
16 April 2014
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From New Scientist #1329, 28th October 1982 [link]
First, place the whole numbers from 1 to 16, one in each square. Next, multiply the numbers in each pair of touching squares and write the product in the little circle between the squares. Finally, add up the numbers in the circles. That gives you the “product-sum”, which you want to make as large as possible.
How big can you make it?
If you follow the Google Books link you will find that this Enigma was published next to a review (and advert) for the book Enigmas by Robert Eastaway, featuring 140 pages of Enigma puzzles selected from New Scientist. I have found a second hand copy of this and ordered it.