I just found out that I passed. I did a lot of practice problems. The books I used include EngrProGuides (Used most often before and during the test), Graffeo, and Complex Imaginary, and PPI exam practice questions. One thing I find helpful was watching youtube on power topics. I think I spent like 300 hours studying. I recommend EngrProGuides guide and test. The other thing that helps is to practice as many questions as you possibly find.
Another thing that I find very helpful is using the calculator efficiency . I have the Casio calculator and it helps me a lot. Every second you save will help.
Lastly, it's best to learn to skip questions. For me, the way I did it was, go through each problem and for the ones that I know how to solve, I will solve it, and for the ones I don't, i just skip it and come back later. Since all problems count the same, no point to waste time on the hard one in first pass.