The link below will download a PDF file with detailed information explaining how they score exams, and in page 2 there's a chart with raw scores and grades that will give you a good idea of what you scored on your exam, especially since you know how many you got correct. There seems to be some math involved, though. Good luck.
http://www.getcollegecredit.com/pdfs/TEC...ET0204.pdf
http://www.getcollegecredit.com/pdfs/TEC...ET0204.pdf