Answer: 61% chance
Explanation:
Since theirs 4 selections and black having the most marbles, we can cancel out green as it has a 10% chance, along with the orange marbles with a 15% chance.
Lastly, the blue marbles are at a high enough number to almost 50/50 the black marbles, BUT since theirs an extra marble w/ the black marbles, it makes it a 61% chance
Try not to lose your marbles as you read this lol