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Puzzle for Today

Puzzle No. 103 – Wednesday November 22

A maths lecturer gets 2 hate-letters for every third Radio 4 puzzle he produces, and 1 in 5 of these is followed up by an apology from the letter-writer. If half the apologies are insincere (and hence null), how many unapologetically hate-filled letters will he have received by his 76th puzzle?

Today’s #PuzzleForToday has been set by Dr Roger Teichmann, Lecturer in Philosophy, St Hilda's College, University of Oxford

The answer to the puzzle is no longer available

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