"What is a journeyman plumber" — how important is this for the JOURNEYMAN exam?

I keep seeing What is a journeyman plumber come up in every study guide and practice test for Journeyman Plumbers Exam.

How heavily does it actually appear on the real exam? I've done about 8 full practice tests now and it shows up constantly, which makes me think it's a high-weight topic — but I want to confirm before I go deep on it.

What I've noticed: the questions on "what is a journeyman plumber" in the practice tests are mostly conceptual, but occasionally they throw in these weird scenario questions where you have to apply the concept in an unusual situation. Those trip me up.

I'm also looking at "how much does a journeyman plumber make" as supplemental material. Is it worth going through that in detail or is the practice test approach enough?

Genuinely curious what percentage of the JOURNEYMAN exam is dedicated to this area.