Using it's concept, it is found that the odds against spinning blue or yellow are given by:
(A) 1:2
The odd of an event is the number of desired outcomes divided by the number of non-desired outcomes.
In this problem:
Hence:
[tex]o = \frac{2}{4} = \frac{1}{2}[/tex]
Which can also be written as 1:2, hence, option A is correct.
To learn more about odds, you can take a look at https://brainly.com/question/25683609