If there are 6 blue marbles and 2 red marbles in a bag, what is the probability of picking a blue marble then another blue marble if you do not replace the first marble P(B,B)? 3/4 x 5/7 or is it 3/4 x 6/7?
Prob = (6/8)(5/7) , which was your first choice
3/4 x 5/7, but that means you presume you took out a blue marble the first time. How do you know that you didn't take out a red marble, so you still have all six blue marbles when you pick the second time?
"... but that means you presume you took out a blue marble the first time"
yes, that is the case we wanted, and the 6/8 is the probability that would have happened, and one of the blue marbles has now been picked.
The Answer is The Probality of picking a pink Or Blue is 4 divide in 2 is 2 1.2
To calculate the probability of picking a blue marble, and then another blue marble without replacement, you need to use the multiplication rule of probability.
The multiplication rule states that the probability of two independent events both occurring is equal to the product of their individual probabilities.
In this case, the probability of picking a blue marble on the first draw is 6/8 (6 blue marbles out of a total of 8 marbles in the bag). After the first draw, there will be 5 blue marbles remaining out of the total of 7 marbles.
Therefore, the probability of picking a second blue marble after the first one has been drawn without replacement is 5/7.
To find the probability of both events occurring, you multiply these two probabilities together:
P(B, B) = (6/8) * (5/7) = 30/56
Simplifying the fraction, we get:
P(B, B) = 15/28
So, the correct answer is 15/28, not 3/4 x 5/7 or 3/4 x 6/7.