Hi there!
#1 - The probability of drawing a blue marble is 845/1200, or approximately 14/20.
#2 - The probability of drawing a green marble is 305/1200, or approximately 5/20.
#3 - The probability of drawing a yellow marble is 50/1200, or approximately 1/20.
Hope this helps!! :)
If there's anything else that I can help you with, please let me know!