The man who loved to count and the incredible story of the 35 camels

Abstract

In 2015, we commemorated the 120th anniversary of the birth of the brilliant Brazilian mathematics professor, storyteller and writer, Julio Cesar de Mello e Souza. Under the pen name of Malba Tahan, he published a seminal book on recreational mathematics that has since been translated into many languages. We reveal the origin of his best-known story, the riddle of the 35 camels to be divided among three sons, where the eldest son was to have one-half of them, the second son one-third and the third one-ninth. This riddle is cleverly solved by adding one camel before dividing them amongst the brothers, and then subtracting two camels afterwards. We provide all the solutions to the more general puzzle in which t jamals (camels) are divided among three brothers assigning some fraction of the total to each one by means of adding one camel before dividing and removing two camels after the division is completed. We also address a controversy related to the origins of this type of puzzle. Finally, we conclude that Tahan, the man who loved to count, really existed