Answer:
There are a total of 25 marbles in the bag.
The probability of choosing a red marble first is 8/25 since there are 8 red marbles out of 25 marbles in the bag.
Since a marble is not replaced after the first selection, there are now 24 marbles in the bag. There are still 3 blue marbles in the bag.
The probability of choosing a blue marble second, after a red marble has already been selected, is 3/24 or 1/8 since there are 3 blue marbles left out of 24 marbles in the bag.
To find the probability of both events occurring together, we multiply their individual probabilities:
8/25 x 1/8 = 1/25
Therefore, the probability that a red marble is chosen first, followed by a blue marble, is 1/25.