For whatever reason, you still have a set of encyclopedias arranged in order on a bookshelf. Each volume has covers 1/8" thick and 1" of pages. One day, a particularly hungry bookworm starts at the first page of Volume 1 and stops eating at the last page of Volume 3. If he ate in a straight line (i.e., the shortest possible distance), how far did he travel?

1.5 inches