The weighing twelve (12) balls riddle – which one is a different weight?

This is a riddle that a friend (Carl “Chunky” Benson) put to me a few years back. A few A4 pages of scribblings and I had accounted for an “answer” for almost all possible outcomes (almost), however, I never arrived at a complete solution. There’s every chance that I’m just hopeless at Maths, so prove […]