Henry Ernest Dudeney/Puzzles and Curious Problems/52 - In the Year 1900/Solution
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Puzzles and Curious Problems by Henry Ernest Dudeney: $52$
- In the Year $1900$
- A man's age at death was one-twenty-ninth of the year of his birth.
- How old was he in the year $1900$?
Solution
- $44$.
Proof
This puzzle was presented in $1932$.
Years immediately before then which are divisible by $29$ are:
- $1827 = 63 \times 29$
- $1856 = 64 \times 29$
- $1885 = 65 \times 29$
- $1914 = 66 \times 29$
The years of death for each of these can then be calculated as:
- $1827 + 63 = 1890$
which is too early, as it is implied he was still alive in $1900$.
- $1856 + 64 = 1920$
which produces the valid solution that he was $44$ in $1900$.
- $1885 + 65 = 1950$
which, in $1932$, is still in the future, so he has not died.
$\blacksquare$
Sources
- 1932: Henry Ernest Dudeney: Puzzles and Curious Problems ... (previous) ... (next): Solutions: $52$. -- In the Year $1900$
- 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Answers: $42$. In the Year $1900$