SOLUTION: There is a bag filled with 3 blue, 4 red and 5 green marbles. A marble is taken at random from the bag, the colour is noted and then it is not replaced. Another marble is taken

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Question 1135954: There is a bag filled with 3 blue, 4 red and 5 green marbles.
A marble is taken at random from the bag, the colour is noted and then it is not replaced.
Another marble is taken at random.
What is the probability of getting exactly 1 blue?

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
first only blue is 3/12*9/11 or 27/132
second only blue is 9/12*3/11 or 27/132
the probability is 54/132 or 0.409
should be complement of no blue (9/12)(8/11) or 72/132
plus both blue (3/12)(2/11) or 6/132, and it is.