David H. answered 01/11/17
Patient and Knowledgeable Math Tutor
I interpret your information this way: The final exam is worth 10% of your final grade. You got a B on your final exam. I'll assume you got an 85% on the exam. Since your grade for the course going into the final exam is a 52%, your final grade for the course is calculated by the following equation.
.1*.85 + .9*.52 = .085 + .468 = .553 = 55.3%