Answer
$\frac{1}{12}$, see below.
Work Step by Step
The sample space should contain 48 possible outcomes in the form of $xyC$ where $x=1,2,3,4$, $y=1,2,3,4$, and $C=$Yellow, Red, or Green.
The final probability is the ratio of all the favorable outcomes over 48, or we can find it by using the product of each individual probabilities, we have
$P=(\frac{1}{4})(\frac{2}{4})(\frac{2}{3})=\frac{1}{12}$
