Since the last issue of Parabola Incorporating Function the mathematics world has been surprised by the appearance of a preprint, dated May 2011, by the German mathematician Gerhard Opfer who claimed to h
As you probably know, a Sudoku puzzle is a $9\times 9$ grid divided into nine $3\times 3$ subgrids. Some of the cells in the grid contain a symbol: usually the symbols are the numbers $1,2,\ldots, 9$.
Here I revisit a topic I have written on several times before, and which furthermore continues the theme of my last column.
In the latter part of year 2009, I attended a scientific talk at Sydney University about the path of a body exiting a cliff. The position at which the body lands from the base of the cliff depends on exit velocity.
Q1361 Find a six digit number which can be split into three two digit squares and also into two three digit squares. (The first digit of a number cannot be zero.)