Grade Average Calculation

For Calculating average grades, we follow the below logic:

Each grade is assigned a numeric value:
A = 95
B = 85
C = 75
D = 65
F = 30

Then, we divide by the total number of grades, to produce the average, given the following conditions:

if (% >= 90) A
if (% >= 80) B
if (% >= 70) C
if (% >= 60) D
else F