What is your grade if you get 4 out of 15?

Answer 1

4 out of 15 right is 27%, which is considered failing.

4 out of 15 wrong is 73% which is usually a C. There are many different ways of grading.

Answer 2

if you get 4 out of 15 right your grade is 4/15 = 0.27 = 27%