The Alan Turing Cryptography Competition

2026 edition. From the people behind the MathsBombe Competition.
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Released Mon 30th Mar 4:00 PM

Chapter 6

Ellie: I also needed help form Caesar! Last one from me. Don't get caught by any circular reasoning.

The image consists of 9 lines of blue decimal numbers: 0.3 0 1.2 2.54 3.29 1.94 2.54 2.69 5.54 1.05 3.59 1.35 4.49 3.89 5.83 0.15 3.74 5.68 4.79 4.49 1.05 4.34 5.39 5.98 0.15 3.74 4.79 1.5 1.05 4.34 3.89 0.45 3.74 5.54 4.64 5.98 1.8 4.79 5.98 2.54 5.98 3.44 2.54 0.15 2.54 0.3 0.15 1.35 5.24 6.13 The numbers are surrounded by a circle of black letters, starting from the top and running clockwise the letters are HOWMANYRADIANSARETHEREINAFULLCIRCLEPLEASE?

The image above contains two questions. Please enter the product of the answers to the two questions in the box below to three decimal places.

To deter guessing without thinking, we ask that you also solve the following simple arithmetic problem before checking your answer:

What is seven multiplied by three, subtract seven?  

This problem was first solved on Mon 9th March at 4:11:31pm
Alan Turing Cryptography Competition 2026 is organised by the The Department of Mathematics at The University of Manchester.
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