# Wrong, but Useful -- Episode 27

podcasts/wbu27.mp3

In this month’s thrilling instalment of the nation’s #1 maths podcast ((Citation needed)) , @reflectivemaths and I discuss…

- The recent leap second
- The number of the podcast, 999,999,999,998,999,999,999,999.
- Farey sequences - introducing the
*mediant*of two fractions - A couple of agreeable sequences, via @pickover
- The number of squares of any size on a chessboard
- The envelopes game
- Callback to traffic studies: visualising shockwaves
- A simple puzzle in the New York Time
- Last episode’s puzzle answer: 53 (we think)
- Puzzle: In a Wimbledon tennis match that goes to five sets, the number of games one of the players wins in each set forms an arithmetic series. Curiously, both players won the same number of games. Who won the match? (A tie-break counts as a game.) I promised the economists and cheats a link to the answer
- Our current reading: both of us have @standupmaths’s Things to Make and Do in the Fourth Dimension. Colin is reading The Numbers Game and recently finished Birth of a Theorem: A Mathematical Adventure.