Helen has 80 books to sell.
Each book is Fiction or Non-Fiction.
The ratio of the number of Fiction books to the number of Non-Fiction books is 3:1.
Each book has a normal price of £10.
Helen reduces the price of all the Non-Fiction books.
[NON-FICTION. ALL BOOKS 1/2 PRICE]
Helen sells all 80 books.
Work out the total amount of money Helen will recieve.