PLEASE HELP with question A

Answer:
1/3%
Step-by-step explanation:
tom has 5 red = 5R
4 blue = 4B
and 3 yellow = 3Y
in total he has 5+4+3=12 marbles
the probability is
(convenient cases)/(total cases)
the convenient cases are when he chooses a blue so there are 4
and the total cases is 12
so we have
[tex]\frac{4}{12} =\frac{1}{3}[/tex]