Answer: \(\dfrac{11}{30}\)
Step-by-step explanation:
Given : The number of red buttons = 7
The number of green buttons = 4
The total number of buttons = 8+4+11+7= 30
The probability of picking a red button is given by :-
\(P(R)=\dfrac{\text{Red buttons}}{\text{Total buttons}}\\\\=\dfrac{7}{30}\)
The probability of picking a green button is given by :-
\(P(G)=\dfrac{\text{Green buttons}}{\text{Total buttons}}\\\\=\dfrac{4}{30}\)
Since both the events are independent then the the probability it is red or green is given by :-
\(P(R\cup G)=P(G)+P(R)\\\\=\dfrac{4}{30}+\dfrac{7}{30}=\dfrac{11}{30}\)
