Answer:
A. 1/3
Explanation:
The probability of drawing a blue marble on the first draw is 2/4, or 1/2, since there are two blue marbles out of four total marbles. After one blue marble has been drawn and not replaced, there are now three marbles left in the bag, one blue and two green. Therefore, the probability of drawing a green marble on the second draw is 2/3.
To find the probability of both events happening, we multiply the probabilities:
P(blue, then green) = P(blue) * P(green after blue)
P(blue, then green) = 1/2 * 2/3
P(blue, then green) = 1/3
Therefore, the probability of drawing a blue marble followed by a green marble, without replacing the first marble before drawing the second marble, is 1/3. Answer: 1/3.