There is a bag filled with 4 blue, 3 red and 5 green marbles. A marble is taken at random from the

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There is a bag filled with 4 blue, 3 red and 5 green marbles. A marble is taken at random from the bag, the colour is noted and then it is replaced. Another marble is taken at random. What is the probability of getting 2 blues?

We have (4 blue + 3 red + 5 green) = 12 total marbles

With replacement, the probability of getting one blue is 4/12 = 1/3

Since each draw is independent of the last, the probability of Blue, Blue = 1/3 * 1/3 = 1/9
 
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