A Book Worm’s Route

          There are there volumes of the same book each three centimeters thick. They are kept in shelf side by side in order. Volume, I, II and III, if a book worm starts outside the front cover of volume I and eats its way through to the outside of the back cover of volume III, travelling in a straight line, how far does it travel?

Answer:  Three Centimetres: The book worm only has to go from the front cover of Volume I to the outside of the book cover of Volume III, in other words he only has to travel through Volume II, which is 3 Centimetres.