The final SAT score is an aggregate of three scores ranging between 200 and 800. The three scores are writing score, math scores, and critical reading score. Thus, the perfect scores are 2400 while minimum possible score 600 (which is practically considered zero).
The total test runs for 3 hours 45 minutes testing time and three breaks of five minutes each. Thus, the total test time is 4 hours including the time allotted for breaks.
Yes, for each correct response, you get a credit of one mark. For each incorrect option, ¼ of a mark is deducted. However, no negative scoring is affected if you leave a question without answering.