A bookworm is eating its way through 3 volumes sitting side by side in order on a library shelf. The covers of each volume are 2.5 mm thick and the pages are 310 mm thick. How far does the worm travel if it starts at the first page of volume 1 to the last page of volume 3?

uswag - 938 mm ?

935

320

We have to ignore the front cover of volume 1 and the back cover of volume 3, but is each leaf of a cover 2.5 mm or is that the thickness of each pair of cover leaves? 935 or 940 mm depending upon the answer to that question.

yes ,lex - agreed ,but i now think it's more like 320 mm ,because it's the spines we should be seeing in our mind ?

enough wine has worn off that i realized - he eats through the front cover of vol.1 ,back cover of 2 and the pages ,then that front cover ,and the back cover of vol.3 to arrive at the end of the book. so 4 covers and one bunch of pages for the 320 mm.
unless i'm still tipsy....

I had taken it that each volume contains pages 310 thick... Niteowl, I think you need more wine rather than less for this...!

My error has been pointed out by Curly, so it is 315 or 320.

Curly said it first but niteowl explained it. He eats through the front cover of volume 1, the back cover of volume 2, the pages of volume 2, the front cover of volume 2, and the back cover of volume 3. 2.5 + 2.5 + 310 + 2.5 + 2.5 = 320.

Well done!