The question says "their intersecting lines form 1,597 areas".
That doesn't suggest finite areas to me, or to most mathematicians.
https://www.mathsisfun.com/definitions/area.htmlThe size of a surface.
The amount of space inside the boundary of a flat (2-dimensional) object such as a triangle or circle.
http://www.merriam-webster.com/dictionary/area2. the surface included within a set of lines
5. a particular extent of space or surface or one serving a special function
If finite areas were meant, it would have been made explicit in the question.
They didn't state the plane is finite, because the definition of a plane doesn't require it.
Your solution should start out by stating that you interpret area to mean finite areas.
Mathematicians don't cite every trivial prior art detail when they write a white paper. We don't regurgitate the definitions of every word we use when we use it.
Anyway, getting back to my question:
What is the maximum number of finite areas created with L lines?
Why is this still relevant?