There are a total of 12 marbles,
4 blue marbles
3 red marbles
5 yellow marbles
First, let us find the probability of drawing a red marble, put it back, and then drawing a yellow marble.
The probability of drawing a red marble is 3/12 or 1/4.
Since we put the red marble back to the box, the total number of marbles stays the same (12 marbles)
Therefore, the probability of drawing a yellow marble is 5/12.
Now, to find the probability of of drawing a red marble, put it back, and then drawing a yellow marble, we will multiply the 2 probabilities together.
[tex]P(R\cap Y)=P(R)\times P(Y)[/tex]
Given that
P(R) = 1/4
P(Y) = 5/12
[tex]P(R\cap Y)=\frac{1}{4}\times\frac{5}{12}[/tex][tex]P(R\cap Y)=\frac{5}{48}[/tex]
Therefore for number 5, the answer would be
[tex]P(R\cap Y)=\frac{5}{48}[/tex]