Answer:
2/13
Step-by-step explanation:
The bag has 6 red, 3 green, 4 blue.
Total marbles = 13
Probability of getting blue the first time would be 4/13 because 4 of the 13 total marbles are blue
Because you're not putting back the first marble, the total would go down to 12, so the probability of getting red the second time would be 6/12 or 1/2
The probability that the first marble is blue and the second marble is red = (4/13)(6/12) = 2/13