a bag contains 8 blue marbles 6 red marbles and 4 green marbles .What is the probability of selecting a blue marble, replacing it in the bag and then selecting a red marble ?
prob = (8/18)(6/18)
= .....
To find the probability of selecting a blue marble, replacing it, and then selecting a red marble, we need to calculate the individual probabilities and multiply them together.
First, let's calculate the probability of selecting a blue marble.
The total number of marbles in the bag is: 8 (blue) + 6 (red) + 4 (green) = 18
So, the probability of selecting a blue marble on the first draw is: 8/18 = 4/9
Since the marble is replaced after selection, the total number of marbles remains the same.
Now, let's calculate the probability of selecting a red marble on the second draw.
The total number of marbles in the bag is still 18.
So, the probability of selecting a red marble on the second draw is: 6/18 = 1/3
To find the overall probability, we multiply the probabilities of each event together.
So, the probability of selecting a blue marble and then a red marble is: (4/9) * (1/3) = 4/27
Therefore, the probability of selecting a blue marble, replacing it, and then selecting a red marble is 4/27.