David Angell's recent article on addition games reminded me of a number game called the Divisor Game.
The ancient Greeks thought about numbers in quite a different way to us.
Many mathematical functions are not readily computable using only a finite sequence of elementary arithmetic operations.
In this short article we will introduce some important notions concerned with the class of convex functions.
Q.931 In a large flat area of bushland there are two fire-spotting towers, one exactly 20km east of the other.
Q.923 On an island there are 50 brown, 57 green, 62 yellow and 68 red frogs.