Question 867107: I have tried it several times but still manage to get a different answer. This is the question: A bag contains 6 black marbles, 4 white marbles, and 5 red marbles.
a) 2 marbles are drawn at random with replacement, find the probability that both marbles are black.
This is what I did: 6/15 * 5/15 and I got 2/15. I ,however, do not think that is the correct answer. My classmate got 4/25. I would appreciate your help very much. Thank you for your consideration.
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! The key here is that each marble drawn is replaced. So you have 6 black marbles (6/15 probability) and once you pull one marble out, you replace it with a new one of the same color or you put it back. That means that the probability of pulling black again is 6/15. The probability does not change as long as you put the marble taken out back into the bag.
So (6/15)*(6/15) = (2/5)*(2/5) = (2*2)/(5*5) = 4/25
making the answer 4/25
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