The books in a private library are classified as fiction and nonfiction. There are 400 books in the library. There are 40 more fiction books than nonfiction books. Audrey randomly picks a book. A few minutes later, Ryan randomly picks one of the remaining books. What is the probability that both pick nonfiction books?

We must first solve the number of fiction and nonfiction books

if x is the number of fiction books and

y is the number of nonfinction books

Then,

x + y = 400

x = y + 40

Solving the system of equations:

x = 220

y = 180

Therefore, the probability that Audrey and Ryan will get both nonfiction books is

P = 180/400 + 179/399

P = 0.8986