On a bookshelf in Quiz Master Shop Towers we have three books in a trilogy. The books are on the shelf in the normal way; that is, volume one on the left, volume two in the middle and volume three on the right.
All three books are two centimetres or 20 millimetres thick, including the covers, and the covers are three millimetres thick.
The puzzle this week is to calculate the distance between the first page in volume one and the last page in volume three.
The obvious way to approach this is that the three books total six centimetres or 60 millimetres and two covers are twice three millimetres or six millimetres, and so arrive at an answer of 54 millimetres.
However this is wrong.
If you examine a book on a shelf you will find that the first page is on the right, not on the left, and vice versa for the last page. So the distance is actually one complete book (20 millimetres) plus two covers (six millimetres) making a total of 26 millimetres.