Thanks to Gordon West and others, the correct answer to each and every question is included. If you read through the pool a few times you'll be amazed at how the correct answer to the question stands out as you are taking your examination for upgrade. You just memorized the questions from the pool and purged the answers on the examination. Now you have your upgrade. It was just the beginning.
Some people are content to just leave it at that.
For others, it has opened the door for further research and study. You can concentrate on learning in depth the material that interests you, and applying that knowledge through practical use utilizing your newly earned privileges. It is up to you to decide how far you want to take it. It's all in how you approach the hobby. The challenge is there if you want it.