Sunday Times Teaser 2719 – Foursums
by H Bradley and C Higgins
A class were given four different non-zero digits and asked to construct rectangles whose sides (in centimetres) were two digit numbers that used all four of these digits.
The class managed to build both the smallest and the largest rectangles that were possible with the given set of digits and found that their areas differed by one half a square metre.
What were the four digits?