Everyone knows how to count the number of elements of a finite set. But what are we actually doing when we count?
A number is prime if it has exactly two factors - itself and unity (one).
What is similar between a drunk staggering along a narrow alley and an electron moving along a wire under a potential difference?
I was recently reading your article on Magic Squares (Vol. 12 No. 1) and I started doing a few.
The game "Life", invented by British mathematician John Conway, is, like Solitaire, a game you can play by yourself.
Your results were, I think, better this year than last. There was a greater willingness to tackle all the questions.
Q.321 The following factorisations of numbers are true: $$12 = 3.4; 1122 = 34.33; 111222 = 334.333; 1111222 = 334.3333 $$
Q.309 In a family with 6 children, the five elder children are respectively 2,6,8, 12 and 14 years older than the youngest.