The FAA private pilot knowledge test is 60 questions in 2.0 hours, and the minimum passing score is 70. That much most people know. What almost nobody is told beforehand is what happens to the questions you get wrong.
Every missed question is reported on your Airman Knowledge Test Report as an ACS code, and your examiner is required to cover those codes during the oral portion of your checkride. Scrape through at 71% and you hand the examiner a list of eighteen topics to work through with you. Walk in at 93% and there are four.
So treat the percentage at the end of this quiz as a study signal rather than a grade. The subject breakdown is the useful part — if airspace comes back at 40% twice in a row, that is where the next two evenings go.
Take it a few times. The twenty questions are drawn at random from the bank each run, so you will get a different mix.