77% or C+
If by grade you mean percentage, you would have scored 67.5%. 40-13= 27 (27/40) * 100
13 - 4 = 9 correct 9/13 x 100 = 69% (rounded)
10/13 right = 77% grade
If you got two wrong out of 15 questions, you would have answered 13 questions correctly. To calculate your grade, you would divide the number of correct answers by the total number of questions and multiply by 100. In this case, (13/15) x 100 = 86.67%. Therefore, your grade would be approximately 86.67%.
You use division. For example 13/47 is approximately 0.276 or 28%. 100-28 is 72 so the grade would be a 72.
77% or C+
12/13 correct is a 92% which is an A-
To calculate your grade, divide the number of correct answers by the total number of questions. If you missed 3 out of 13 questions, you got 10 correct. Therefore, your grade would be 10/13, which is approximately 76.9%. Depending on the grading scale, this would typically be a C or C+.
2 wrong out of 13 means 11 right out of 13 11/13 = 84.6% This typically translates to a solid B on many, if not most, grading scales. At Hogwarts it would probably be an A (Acceptable) - or possibly E (Exceeds Expectations) YMMV
84.6 around that
54% or F
8/13 right = 62 %