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Sunday Times Teaser 2667 – Prime Time

by Peter G Chamberlain

I wrote an A next to one number on a diagram of a clock face and then moved a number of hour positions clockwise and wrote a B.

I continued in this way using the same number of clockwise steps to write all the following letters so that they each had a corresponding number.

I noticed that the two numbers with three letters by them were both prime.

I also noticed that if I wrote the numbers for PRIME in order to form a long number, I obtained a six-digit prime.

What numbers correspond to A and B respectively?

3 Comments Leave one →
  1. brian gladman permalink

    This uses my prime class provided under the ‘Python’ menu above.

  2. Here is my version, using a simple sieve to generate primes:

  3. ahmet cetinbudaklar permalink

    E must be either 1 or 3 or 7 or 9 or 11 to let PR?ME be a prime number as well as step lengths must not necessarily be factors of 12 , then it is a matter of trial and error to get the solution.

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