As LynW stated if you didn't receive a passing grade (70% or higher) on your first try you will be allowed one retake after 24 hours and up to 30 days after. On that retake the highest grade you will be able to receive is a 70%. To clarify even if you sore 100% on the retaken exam you will only get credit for the 70% since that is the highest grade possible on a retake.
Best of luck,
Myria
Multi-year student ambassador