I took algebra 1 5 times before passing (needed a C, got several d’s and f’s.) I passed geometry on the first try, needed 2 tries for alg 2 and trig. I completely forgot everything after alg 1 since. (The last math class I took was in 1992.)
However, I still teach math. I only teach up to SAT math. However, I scored a 760/800 on the GRE for math, and I could probably get a perfect score on SAT math now. Recently, I took the placement tests at a local community college as part of my job as administrator for a test-prep program. I didn’t study. I had perfect scores on both the math and verbal sections (the placement test goes up to grade 16, grade 12 would be a high school graduate. I scored a 16.9 in both sections.)
If you are prepping for it, remember that strategies for these tests are incredibly powerful.