Answer:
1/3
Explanation:
There is a bag of marbles. If you add all of them together you get 18 marbles total. Marbles are red, 6 are purple, and 6 are yellow. Since each color is 1/3 of the bag ( 18 divided by 6 is 3) you will of have 1/3% chance of getting a yellow marble. 1/3 is equal to 33.3%.