Let G = HW1 + HW2 + HW3 + EX1+ EX2 
Range  of G  [0,477]

If   the semester was to end NOW (10/23)
and based on this information only and nothing else

 and   380 <= G <= 477  ---> A
       325 <= G <= 380  ---> B or B+
       230 <= G <= 325  ---> C or C+
         0 <= G <= 230  ---> D or F
 Ranges may overlap.


Oct 23, 2018 @ 10:00