Answer:
7/11
Explanation:
Given;
Total number of marbles = 11
Number of marbles with red on them = 7
Number of marbles with blue on them = 4
Number of marbles with green on them = 6
Number of marbles with red and green on them = 6
We'll use the below formula to determine the probability that a randomly chosen marble has either green or red on it;
[tex]P(G\cup R)=P(G)+P(R)-P(G\cap R)[/tex]where;
[tex]\begin{gathered} P(G\cup R)=\text{ the probabilty of choosing a marble with green or red on it = ?} \\ P(G)=\text{ the probability of choosing marbles with gre}en\text{ on them }=\frac{6}{11} \\ P(R)=\text{the probability of choosing marbles with red on them}=\frac{7}{11} \\ P(G\cap R)=\text{the probability of choosing marbles with gre}en\text{ and red on them }=\frac{6}{11} \end{gathered}[/tex]Let's go ahead and substitute the above values into the formula and evaluate;
[tex]\begin{gathered} P(G\cup R)=\frac{6}{11}+\frac{7}{11}-\frac{6}{11} \\ P(G\cup R)=\frac{7}{11} \end{gathered}[/tex]