5 ms·

What is your objection to question #13? I suppose the question doesn’t mention that volume 1 is on the left and volume 2 is on the right but I guess that would

What is your objection to question #13? I suppose the question doesn’t mention that volume 1 is on the left and volume 2 is on the right but I guess that would be assumed by any speakers of left to right languages.

frostirosti 5y ago
could also be the case that the two volumes are empty, ie have no pages
- Jtsummers 5y ago
  The problem statement gives us that there are 2cm of pages in each book. So they are not empty. The confusion is in which order the books would be on the shelf, and consequently which direction the bookworm would be moving and through what.
- valbaca 5y ago
  what book has no pages? Also the problems states: > The pages of each volume are 2 cm thick
- thaumasiotes 5y ago
  The pages would be less than 20mm thick in that case.
- deleted 5y ago
  [deleted]
thaumasiotes 5y ago
> I suppose the question doesn’t mention that volume 1 is on the left and volume 2 is on the right but I guess that would be assumed by any speakers of left to right languages. The answer is supposed to be 4mm; the only way for that to work if volume 1 is on the left is for the bookworm to gnaw its way out of the book from v.1.p.1, cross the outside of the two books without gnawing anything until it reaches the back cover of volume 2, and then gnaw its way through that cover to reach the final page of volume 2. I don't think that's what the question has in mind. The point of being a bookworm is that you don't leave the book. So the answer would appear to require that volume 2 is shelved in front of volume 1. I don't know why that would be the case.
- SamBam 5y ago
  This is incorrect. You seem to be making the same error as the author says the editors made in the footnote at the bottom. If volume 1 is on the left, and the worm goes from page 1 of volume 1 to the last page of volume 2, it travels 4mm in a straight line. Page 1 of volume 1 and the last page of volume 2 will be right next to each other, if volume 1 is on the left.
  - meristem 5y ago
    Wow, this relies on both books being in the same orientation, with front cover to the right. It assumes a lot. For perspective, I for years kept books shelved upside down because that orientation was easier for me when reading spines.
    - SamBam 5y ago
      I guess it relies on the books being ordered and arranged the same way they'd be in every single bookstore and library in the world (in left-to-right ordering countries). But it's true, maybe this is too much to assume. Most of the time when I've seen this puzzle it's shown the book spines in an image to make it clear, and many people still can't get it. Then again, that would rely on knowing whether it was using top-to-bottom or bottom-to-top book title orientation, so perhaps the only solution is for the author to spell out "the first page of volume 1 is next to the last page of volume 2."
      - 3np 5y ago
        > in every single bookstore and library in the world Not so fast. Some cultures (Japan for one, I think China and Taiwan as well?) have page-ordering right-to-left but books are generally stacked left-to-right from what I've seen (and in ether case bookstores don't order volumes differently depending on if it's native right-to-left books or foreign right-to-left ones).
    - anyfoo 5y ago
      German books have the orientation of the writing on the spine flipped. I don't like storing books upside down, so it makes a mess in my mixed English and German bookshelf.
maratc 5y ago
The point with this question is that if volume 1 is on the left and volume 2 is on the right, the first page of volume 1 is facing right and the last page of volume 2 is facing left, so the only thing between them is the two covers. Hence, the answer is 4 mm.
soperj 5y ago
It also assumes that the pages aren't facing out.

frostirosti 5y ago

could also be the case that the two volumes are empty, ie have no pages

Jtsummers 5y ago
The problem statement gives us that there are 2cm of pages in each book. So they are not empty. The confusion is in which order the books would be on the shelf, and consequently which direction the bookworm would be moving and through what.
valbaca 5y ago
what book has no pages? Also the problems states: > The pages of each volume are 2 cm thick
thaumasiotes 5y ago
The pages would be less than 20mm thick in that case.
deleted 5y ago
[deleted]

thaumasiotes 5y ago

> I suppose the question doesn’t mention that volume 1 is on the left and volume 2 is on the right but I guess that would be assumed by any speakers of left to right languages. The answer is supposed to be 4mm; the only way for that to work if volume 1 is on the left is for the bookworm to gnaw its way out of the book from v.1.p.1, cross the outside of the two books without gnawing anything until it reaches the back cover of volume 2, and then gnaw its way through that cover to reach the final page of volume 2. I don't think that's what the question has in mind. The point of being a bookworm is that you don't leave the book. So the answer would appear to require that volume 2 is shelved in front of volume 1. I don't know why that would be the case.

SamBam 5y ago
This is incorrect. You seem to be making the same error as the author says the editors made in the footnote at the bottom. If volume 1 is on the left, and the worm goes from page 1 of volume 1 to the last page of volume 2, it travels 4mm in a straight line. Page 1 of volume 1 and the last page of volume 2 will be right next to each other, if volume 1 is on the left.
- meristem 5y ago
  Wow, this relies on both books being in the same orientation, with front cover to the right. It assumes a lot. For perspective, I for years kept books shelved upside down because that orientation was easier for me when reading spines.
  - SamBam 5y ago
    I guess it relies on the books being ordered and arranged the same way they'd be in every single bookstore and library in the world (in left-to-right ordering countries). But it's true, maybe this is too much to assume. Most of the time when I've seen this puzzle it's shown the book spines in an image to make it clear, and many people still can't get it. Then again, that would rely on knowing whether it was using top-to-bottom or bottom-to-top book title orientation, so perhaps the only solution is for the author to spell out "the first page of volume 1 is next to the last page of volume 2."
    - 3np 5y ago
      > in every single bookstore and library in the world Not so fast. Some cultures (Japan for one, I think China and Taiwan as well?) have page-ordering right-to-left but books are generally stacked left-to-right from what I've seen (and in ether case bookstores don't order volumes differently depending on if it's native right-to-left books or foreign right-to-left ones).
  - anyfoo 5y ago
    German books have the orientation of the writing on the spine flipped. I don't like storing books upside down, so it makes a mess in my mixed English and German bookshelf.

maratc 5y ago

The point with this question is that if volume 1 is on the left and volume 2 is on the right, the first page of volume 1 is facing right and the last page of volume 2 is facing left, so the only thing between them is the two covers. Hence, the answer is 4 mm.

soperj 5y ago

It also assumes that the pages aren't facing out.