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nydus/The Canterbury Puzzles, and Other Curious ProblemsPublic

Henry Ernest Dudeney collects a wide variety of original mathematical and mental puzzles into this volume. The book features an introductory essay on the nature of puzzles and provides solutions for all problems at the end.

Page 221 of 307
Table of Contents

47 .— The Riddle of St. Edmondsbury.

n = 14 = 1,111,111 × 10,000,001

n = 18 = 111,111,111 × 1,000,000,001

In the above two tables n is of the form 4m + 2. When n is of the form 4m the factors may be written down as follows:—

n= 4 = (11) × (101)

n = 8 = (11) × (101) × 10,001

n = 12 = (11) × (101) × 100,010,001

n = 16 = (11) × (101) × 1,000,100,010,001.

When n = 2, we have the prime number 11; when n = 3, the factors are 3 . 37; when n = 6, they are 11 . 3 . 37 . 7. 13; when n = 9, they are 32 . 37 . 333,667. Therefore we know that factors of n = 18 are 11. 32 . 37 . 7 . 13 . 333,667, while the remaining factor is composite and can be split into 19 . 52579. This will show how the working may be simplified when n is not prime.

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