Answer :
Answer: [tex]\dfrac{1}{220}[/tex]
Step-by-step explanation:
Given
There are 3 marbles of red, blue, green and orange
Total marbles are 12
No of ways of choosing 3 green marbles out of 3 green marbles is [tex]^3C_3[/tex]
Total no of ways of selecting 3 marbles out of 12 are [tex]^{12}C_3[/tex]
So, the probability is
[tex]\Rightarrow P=\dfrac{^3C_3}{^{12}C_3}=\dfrac{1\times 3\times 2\times 1}{12\times 11\times 10}\\\\\Rightarrow P=\dfrac{1}{220}[/tex]