Sentence error

Welcome to the Forum.

I came across a sentence in a test this morning, which goes,
"The first twenty to thirty pages of James Joyce would give any reader a big headache. Fortunately, the rest pages are not hopelessly difficult."
The test taker is required to copy the original sentence with errors corrected if there's any. I will change it to
"The first twenty to thirty pages of the work by James Joyce would give any reader a big headache. Fortunately, the rest of the pages are not hopelessly difficult." 
The only strictly grammatical error in the original is that it should be 'the rest of the pages'.

By adding 'the work by', you are not correcting the grammar, although you are clarifying the meaning
You might also say, eg  'of any work by' or 'of every work by'.

But I am not sure of this revision. I remember Ulysses---the whole of it---is a big headache, so I will not say "The first twenty to thirty pages of Ulysses by James Joyce would give any reader a big headache. Fortunately, the rest of the pages are not hopelessly difficult." What you are saying here is that you disagree with the sentence writer's meaning. In a grammar test, thtat is not really what you are expected to do. But if you really wanted to, you could say

"Ulysses, by James Joyce, would give any reader a big headache."
 
Best wishes, Clive

Hi,
 Thanks for your explanation. So, you mean I only need to change "the rest pages" to "the rest of the pages" or "the rest of the book/ novel" while keeping the other parts of the original sentence intact, including "The first twenty to thirty pages of James Joyce",do you? Yes.

"The first twenty to thirty pages of James Joyce" just means "The first twenty to thirty pages of the work or  book or novel  by James Joyce" in this situation, right? I remember we can say "Someone likes to read James Joyce or Jack London or Shakespeare or any other author", but I haven't come across "of James Joyce or any other author" before. Yes, it's said. It usually means the first 20 or 30 pages written by this author that you read, no matter which of his books you start with'.

And this is why I inserted "the work by". It's not wrong, but it means a specific work, that the reader should be already aware of. That's why I think I suggested the non-specific form 'any work / any novel'. 

As for Ulysses,  I meant to say that if I had used "Ulysses" instead of  the comparatively vague words "the work", the sentence I then got would have been wrong in meaning. Please do me a favour and help me get clear about all this?
It's OK to talk specifically about Ulysses, but the original sentence did not just deal with Ulysses.

Clive