a.
[tex]\frac{14}{20}=\frac{7}{10}=0.7[/tex]Therefore, your score would be 70% then you will get a C
b.
[tex]\frac{66}{80}=\frac{33}{40}=0.825[/tex]Your score would be 82.5%, then you will get a B
c.
[tex]\frac{216}{250}=\frac{108}{125}=0.864[/tex]Your score would be 86.4%, then you will get a B