Answer
$P(Excellent)=\frac{53}{90}\approx0.589$
Work Step by Step
$N(A)=1+8+21=30$.
$N(B)=0+11+19=30$.
$N(C)=6+11+13=30$.
$Total=N(A)+N(B)+N(C)=90$.
$N(Excellent)=21+19+13=53$.
$P(Excellent)=\frac{N(Excellent)}{Total}=\frac{53}{90}\approx0.589$
