how much percent of a book goes to the writer?

Question

I wonder if a writer earns money for the amount of books he sells or the publish company gives him some payment

Answer 1

I think it depends of what country you're in, but in Belgium, it's not that much...
The writer get 20 to 30 %. The rest goes to the publisher, the production costs, the book store... etc.

Some publishers give writers a contract to write 2 books or more. While they're working on it, they'll receive a monthly wage.