Here’s the response we got from Sheth Publications:

The approach to the subject is what makes a book different and a success and a failure depending on the acceptability by the students.
Ask any Author / Publisher and a whole lot of deficiencies will be pointed out from rival books.
Basically it is the coverage of the subject which is very important.
If the coverage of the content is good without repetition then any no of questions can be attempted whether given or not.
No book can be complete as every student has followed different Professors in various Colleges ad the approach is varied and hence the statement that no book is complete.
The important is that the syllabus is covered in the book in a lucid and easy to understand format which is what our book does.
This is all we can say for our books which ever the subject.