From New Scientist #660, 31st July 1969 [link]
Barbara Bocardo, the well-known lady logician, has developed a weakness for the occult. The other day she dropped in on a clairvoyance experiment run by Dr Divine at the Parapsychology Lab. He had a table on which five cards, numbered one to five, were lying face down.
“The cards have been drawn at random from a pack containing 10 of each of five different kinds of card”, he explained. “My five subjects over there have written down a guess for each card. In a moment I shall turn up the cards and score their guesses”.
Our heroine spent a moment studying the guesses, which were:
“What results would you expect?”, she asked.
“The standard result is what I call a 2-1-0 run”, Dr Divine replied.
“One subject scores 2, three score 1, one scores 0. One symbol comes up twice, three come up once and one doesn’t come up at all. One card is guessed by two subjects, three by one, and one is not guessed at all”.
“Do let me try!”, exclaimed the lady, writing down her guess.
The run was a standard one and Barbara Bocardo proved 100 per cent clairvoyant.
What did she guess?
This puzzle is also included in the book Tantalizers (1970).
It is the final puzzle in the book that I have been able to identify as previously published in New Scientist. Which leaves 12 unidentified puzzles in the book.
[tantalizer110]