Sunday Times Teaser 3037 – Prime Advent Calendar
by John Owen
Published Sunday December 06 (link)
Last year I was given a mathematical Advent calendar with 24 doors arranged in four rows and six columns, and I opened one door each day, starting on December 1. Behind each door is an illustrated prime number, and the numbers increase each day. The numbers have been arranged so that once all the doors have been opened, the sum of the numbers in each row is the same, and likewise for the six columns. Given the above, the sum of all the prime numbers is as small as it can be.
On the 24th, I opened the last door to find the number 107.
In order, what numbers did I find on the 20th, 21st, 22nd and 23rd?