Henry Ernest Dudeney/Modern Puzzles/51 - An Exceptional Number/Solution
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Modern Puzzles by Henry Ernest Dudeney: $51$
- An Exceptional Number
- A number is formed of $5$ successive digits (not necessarily in regular order)
- so that the number formed by the first $2$ multiplied by the central digit will produce the number expressed by the last $2$.
Solution
We have:
- $1 \, 3 \, 4 \, 5 \, 2$
as:
- $13 \times 4 = 52$
It remains to be shown that there are no more.
This could be implemented by means of a computer search.
Sources
- 1926: Henry Ernest Dudeney: Modern Puzzles ... (previous) ... (next): Solutions: $51$. -- An Exceptional Number
- 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Answers: $102$. An Exceptional Number