You are testing a system that calculates the final course grade for a given student. The final grade is assigned based on the final result, according to the following rules:  0 – 50 points: failed  51 – 60 points: fair  61 – 70 points: satisfactory  71 – 80 points: good  81 – 90 points: very good  91 – 100 points: excellent You have prepared the following set of test cases: Final Final result grade TC1 91 excellent TC2 50 failed TC3 81 very good TC4 60 fair TC5 70 satisfactory TC6 80 good What is the 2-value Boundary Value Analysis (BVA) coverage for the final result that is achieved with the existing test cases?