There are three glasses on the table - 3, 5, and 8 oz. The first two are
empty, the last contains 8 oz of water. By pouring water from one glass
to another make at least one of them contain exactly 4 oz of water.
Siméon Denis Poisson (1781-1840) was a famous French mathematician of the last century. He worked in celestial mechanics, probability, calculus, electricity and magnetism. He is known to be designated for a medical carreer by his family. Edward Kasner and James Newman (Mathematics and the Imagination) refer to Poisson's biographer, Arago:
Siméon Poisson's family tried to make him everything from a surgeon to a lawyer, the last on the theory that he was fit for nothing better. One or two of these professions he tackled with singular ineptitude, but at last he found his métier. It was on a journey that someone posed to him a problem similar to the one below (above on this page - AB). Solving it immediately, he realized his true calling and thereafter devoted himself to mathematics, becoming one of the greatest mathematicians of the nineteenth century.
