Answer:
Total number of marbles = 18
Number of green marbles = 8
Number of ways to choose 3 green marbles = [tex]8C_3[/tex]
Number of ways to choose 3 marbles from the total 18 marbles= [tex]18C_3[/tex]
Probability 0f choose 3 green from 18 marbles
= [tex]\frac{8C_3}{18C_3}[/tex]
= 0.0686 = 6.9%