Why the world's toughest maths problems are much harder than a chess puzzle, and well worth US$1m
Peter Nightingale (left) and Ian Gent with two of the eight queens needed for the '8-queen' problem. Stuart Nicol/University of St Andrews, Author provided
The above picture shows a chessboard with two queens placed on it. As the queens do not share the same row, column or diagonal of the chessboard they are not attacking each other. Can you place another six queens on the board so that none of the eight queens are attacking each other? And if it’s possible, how many ways are there to do it?
Читать дальше...