So here is a puzzle that occurred to me while running yesterday (I know, I know, I need to get a life 🙂 ) Two runners start from point A and run at uniform (but different from each other) speeds to a point B exactly a mile apart and run back and keep doing this till they meet at either end (A or B). If their speeds are “m” mins/mile and “n” mins/mile (m not equal to n, and m and n are whole integers), how would you find out after how many minutes will they meet (they stop if they meet at A or B)?