Henry Ernest Dudeney/Puzzles and Curious Problems/63 - Westminster Clock/Solution
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Puzzles and Curious Problems by Henry Ernest Dudeney: $63$
- Westminster Clock
- A man crossed over Westminster Bridge one morning between eight and nine o'clock by the tower clock
- (often mistakenly called Big Ben, which is the name of the large bell only. But this is by the way).
- On his return between four and five o'clock he noticed that the hands were exactly reversed.
- What were the exact times he made the crossings?
Solution
He travelled out at $08 : 23 \tfrac {71} {143}$ and returned at $04 : 41 \tfrac {137} {143}$.
Proof
See Ambiguous Times for a full analysis.
$\blacksquare$
Sources
- 1932: Henry Ernest Dudeney: Puzzles and Curious Problems ... (previous) ... (next): Solutions: $63$. -- Westminster Clock
- 1968: Henry Ernest Dudeney: 536 Puzzles & Curious Problems ... (previous) ... (next): Answers: $55$. Westminster Clock