on my shelf i have a three-volume set of encyclopedias, shelved in the usual order. each volume is 2 inches thick, with the front and the back covers accounting for 1/4 inch each and the pages accounting for 1 and 1/4 inches. one day, a hungry bookworm, starting on the first page of volume 1, burrowed its way through pages and covers until it reached the last page of volume 3. how far did the bookworm travel?