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Summer Maths Puzzles - Wednesday 28 August - Doors to your Destiny

​​Doors to your Destiny

  1. You are imprisoned in a land where analytical reasoning is prized more highly than guilt or innocence.  The prison guard brings you to 2 green doors A and B with signs on them and truthfully tells you that for all pairs of green doors you may encounter, the sign on one door is true and the sign on the other is false. 

  1. Having successfully avoided death in the first challenge you proceed along the corridor only to find yourself facing a pair of blue doors. The guard truthfully tells you that for blue doors, the signs are either both true or both false.

Which door do you choose?

  1. Having avoided death once more you proceed along the corridor only to find yourself facing another pair of blue doors.

Again, which door do you choose?


Please email your answers to deputy-director[at][dot]uk and remember to include your name (or the name of the group that you solved the puzzle with) so that we can publish it on our website if you are one of the first few to successfully solve the problem.  

Answers to all puzzles will be published at the end of the month. 

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    Clay Mathematics Institute London Mathematical Society NM Rothschild and Sons