Answer:
5/33
Step-by-step explanation:
There are a total of (4 + 5 + 3), or 12, marbles at the onset. The probability of drawing a blue marble then is 5/12. If on the first draw a blue marble comes up and is not replaced in the bag, then there are 4 remaining blue marbles out of 11 marbles, and so the probability of drawing a blue marble is 4/11.
Multiplying these two probabilities together, we get (5/12)(4/11) = 20/132, or 5/33.
