p(event) = (number of ways desired outcome can happen)/(total number of outcomes)
The total number of outcomes is based on drawing any marble of any color. It is the the total number of marbles which is 5 + 24 + 12 + 18 = 59.
The desired outcome is to draw a green marble. Since there are 24 green marbles, the number of desired outcomes is 24.
p(green) = 24/59
p(green) = 0.406779...
Answer: 0.41