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Robert Kanigel: 2 puzzles worth knowing

2 puzzles from Robert Kanigel, each explained in a minute and credited to the original work. Free on Savvy.

• The dullest number in a taxi's licence plate

  Visiting a sick Srinivasa Ramanujan in hospital, G. H. Hardy mentioned he'd arrived in taxi number 1729, calling it 'rather a dull number'. Ramanujan disagreed instantly. What did …

  — Robert Kanigel, The Man Who Knew Infinity

• Told a puzzle mid-conversation, he gave every possible answer at once

  On a street, houses are numbered consecutively starting from 1. On one particular house, the sum of all house numbers before it exactly equals the sum of all house numbers after it…

  — Robert Kanigel (recounting P. C. Mahalanobis's account), The Man Who Knew Infinity

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