The probability that an event A or an event B occur, is given by:
[tex]P(\text{AorB)}=P(A)+P(B)[/tex]
The probability of getting a grey ball is P(A)=0.053 and the probability of getting a green ball is P(B)=0.126.
So, the probability of getting a grey or a green ball is:
[tex]P(\text{AorB)}=0.053+0.126=0.179[/tex]
Answer: 0.179
