Sales of Fiction and Non-Fiction Novels

In a small bookstore, the owner decided to sell two types of novels: fiction and non-fiction. Let F represent the number of fiction novels sold, and N represent the number of non-fiction novels sold. During a two-week sales period, the owner sold a total of 120 novels. The number of fiction novels sold is three times the number of non-fiction novels sold. How many fiction novels did the owner sell?

The situation can be expressed using the following equations:

1. $$F + N = 120$$

2. $$F = 3N$$