Henry Ernest Dudeney/Modern Puzzles/51 - An Exceptional Number
Jump to navigation
Jump to search
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 $2$.
- Thus if it were $1 \, 2 \,8 \, 9 \, 6$, then $12$ multiplied by $9$ produces $96$.
- But, unfortunately, $1, 2, 6, 8, 9$ are not successive numbers, so it will not do.
Click here for solution
Variant
- A number is formed of $6$ successive digits (not necessarily in regular order)
- so that the number formed by the first $2$ multiplied by the $3$rd digit will produce the number expressed by the last $3$.
Sources
- 1926: Henry Ernest Dudeney: Modern Puzzles ... (previous) ... (next): Arithmetical and Algebraical Problems: Digital Puzzles: $51$. -- An Exceptional Number
- 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Arithmetical and Algebraical Problems: Digital Puzzles: $102$. An Exceptional Number