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Everyday science

Quiz question of the week

12 May 2011 Matin Durrani

By Matin Durrani

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I always find it interesting when little-known anecdotes about some of the greatest figures in physics come to light.

So here’s one that I thought I’d share with you, courtesy of Uri Haber-Schaim, a retired physicist now living in Jerusalem.

Writing in the latest issue of Il Nuovo Saggiatore – the bulletin of the Italian Physical Society – Haber-Schaim recalls a summer school in high-energy physics that took place in Varenna, Italy, in 1954, which was attended by, among others, the Italian particle physicist Enrico Fermi.

During the morning break, one of the participants from France – A Rogozinsky – posed a mathematical problem concerning a priest and a sexton on a walk who encounter three people coming towards them.

The sexton asks the priest how old the three people are and is told that “the product of their ages is 2450 and the sum of their ages is twice your [i.e. the sexton’s] age”.

The sexton, saying that he needs more information to solve the problem, is then told by the priest that he – the priest – is “older than any of them”.

So the question is: what are the ages of the three people, the priest and the sexton?

Haber-Schaim recalls that everyone at the meeting realized that writing down equations would not get them anywhere and that he then suggested to Rogozinksy that he present the problem at lunch so that everyone could tackle it together.

Fermi, however, who was a notoriously good problem solver, proceeded to answer the puzzle within a minute.

So over to you, physicsworld.com readers. Can you solve the problem or – even better – beat Fermi and get the answer in under a minute?

For the record, I still haven’t figured it out.

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