We have 3 sections.
[tex]\sf~Red=\dfrac{11}{20}[/tex]
[tex]\sf~Blue=\dfrac{6}{20}[/tex]
So the entire spinner is divided into [tex]\sf20[/tex] sections.
Since we only have 3 sections(red, blue, green) we can add red and blue, and subtract 1 or 20/20.
[tex]\sf\dfrac{11}{20}+\dfrac{6}{20}\rightarrow\dfrac{11+6}{20}\rightarrow\dfrac{17}{20}[/tex]
Subtract:
[tex]\sf\dfrac{20}{20}-\dfrac{17}{20}=\boxed{\sf\dfrac{3}{20}}[/tex]
So the probability that the arrow landing on a green-colored section is [tex]\sf\dfrac{3}{20}[/tex].
