Answer:
1/12
Step-by-step explanation:
The initial probability of drawing a blue marble would be 3/9 as there are initially 3 blue marbles and in the bag there are a total of 9 marbles however, to get the second blue marble, the probability would be 2/8 since there's one less blue marble in the bag, making it 2 and one less marble in the bag, in general, leaving 8 marbles in the bag. To find the combined probability of getting both blue marbles, multiply the probabilities so:
3/9 x 2/8 = 1/3 x 1/4 = 1/12