Answer: 90%
Explanation:
Step 1: Calculate the total number of marbles in the bag.
3 red + 3 green + 15 yellow + 9 purple = 30 marbles
Step 2: Calculate the number of marbles that are not red.
3 green + 15 yellow + 9 purple = 27 marbles
Step 3: Calculate P(not red).
27/30 = 0.9
Answer: 90%