Enigma 1015: Money-spinner
13 April 2019
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From New Scientist #2171, 30th January 1999 [link]
In my local pub there is an electronic “slot machine” which offers a choice of various games. In one of them, called Primetime, after inserting your pound coin the 9 digits 1-9 appear in random order around a circle. Then an arrow spins and stops between two of the digits. You win the jackpot if the two-digit number formed clockwise by the two digits on either side of the arrow has a two-figure prime factor. So, if the digits and arrow ended up as above, you would win the jackpot because 23 is a factor of 92.
However, with the digits in the same position but with the arrow between 8 and 1 you wound not win.
I recently played the game. The digits appeared and the arrow started to spin. But I realised to my annoyance that, no matter where the arrow stopped, I could not with the jackpot.
Starting with 1, what is the clockwise order of the digits?