Long time lurker, first time poster. Took the OAR on Tuesday and scored a 65. Really surprised and happy with my score because I truly thought I bombed the reading. I was more nervous for this exam than anything in my life and I wanted to share some details to try to make some non-STEM majors feel more confident going in. For those wondering, I am a political science major with a 3.42 GPA hoping to be selected SWO. (This is just my experience with the OAR)
Pre-exam: Starting out, I didn't even understand what D=R*T meant. I studied and researched a lot for this exam. As many people said before me, make sure you look through countless threads on this forum because they are invaluable to your success. I ordered the Trivium book which helped a lot in the mechanical comprehension portion but the math was just ok. DO NOT get the Mometrix book, it's a waste of money. Essentially, everything you need is right in this forum. I printed out every practice exam on AR and went over each question at least 3-4 times. I don't have a background in math or engineering so I focused most of my time understanding the concepts and making sure I could do any problem the exam threw at me.
Math: Every question I had, I had seen before one way or another. I had a couple probability problems, D=RT where one person was going 8 mph and had 6 miles left in a race and another person was going 10 mph and had 8 miles left - find the time between the two finishes, one log that was logx(√2)= 1/6, one multiplying matrices, perfect numbers, and how many cones can fit inside a cylinder (they give you the formulas). Know your exponent rules and system of equations. I didn't take the full 40 minutes and it kicked me out with 6-7 minutes left. The harder the questions get, the better you are doing.
Reading: Like I said before, the reading was pretty tough. The answers can go either way so I suggest reading the passage twice through then answering. One thing I wasn't aware of was the format of the answers. The test is just a passage and then A,B,C, and D. There's no "what's the main idea..." or "the topic of this passage is..." leading into the answers. Maybe I didn't know because I really didn't focus much on this section. I forget where, but someone mentioned writing ABCD on your scrap paper and eliminating answers which actually helped and made things less confusing. Time expired for me here.
Mechanical: This goes by really quick. Only three answers to choose from, which was nice. Honestly, I don't remember specific questions but I know I had to apply Newton's Laws a couple times. Make sure you focus on understanding pressure and pistons. Know how to get the Mechanical Advantage for all simple machines and know gears in and out. Ended on a nuclear question which I think is floating around in this thread somewhere.
Overall, I really think this exam is confidence and preparation. My goal going in was around a 50 and I got a score I didn't even think I was capable of. If anybody wants to pick my brain about the exam, I'd be happy to share more. Hopefully I get to meet all of you along the way.