Answer :
P(blue)= 0.15
P (red)=0.04
P(blue, red)=0.06
Explanation
The probability of an event is the number of favorable outcomes divided by the total number of outcomes possible
Step 1
fin the total of outcomes possivle
[tex]3\text{ blue marbles+4 yellow marbles +5 greeen marbles+8 red marbles= 20marbles}[/tex]Step 2
to fin P( blue)
let
number of favorable outcomes= number of blue marbles= 3,then
[tex]\begin{gathered} P(\text{blue)}=\frac{3}{20}=0.15 \\ P(\text{blue)}=0.15 \end{gathered}[/tex]Step 3
to fin P( red)
let
number of favorable outcomes= number of red marbles=8,then
[tex]P(\text{red)}=\frac{8}{20}=0.4[/tex]Step 4
finally, if you pick 2 marbles without replacing, Find (blue, red)
[tex]P(\text{blue, red)=}\frac{3}{20}\cdot\frac{8}{19}=\frac{24}{380}=0.06[/tex]note that the total of outcomes for the second event is 19, because we already subtracted 1 marble.
I hope this helps you , have a great day