In a library, in one of the rack there are 4 books kept continuously. Volume 1 to volume 4.
For each book the front cover thickness is 1/6 inch and the back cover is 1/6 inch also the thickness of the page is 2 inch(all the pages of one book). therefore each book is 7/3 inch. Now consider a worm which starts to eat the book. It starts from page one of volume 1 and makes a hole and eats till last page of volume 4. The worm travels in straight line.
Now calculate the distance(in inch) traveled by the worm in making the hole.