Final answer:
The probability of getting 2 red marbles is 36/121.
Step-by-step explanation:
To find the probability of getting 2 red marbles, we need to consider the probability of getting 1 red marble on the first draw and then another red marble on the second draw.
There are a total of 5 blue and 6 red marbles in the bag.
Since we are replacing the marble after each draw, the probability of getting a red marble on the first draw is 6/11.
Since we replaced the marble, there are still 5 blue and 6 red marbles in the bag.
Therefore, the probability of getting a red marble on the second draw is also 6/11.
To find the probability of both events happening, we multiply the probabilities together:
= (6/11) * (6/11)
= 36/121.
So, the probability of getting 2 red marbles is 36/121.