Answer:
For this problem you will be multiplying 3 probabilities together: P(#1 is blue)*P(#2 is blue)*P(#3 is blue). For the first probability, we just need to divide the number of blue marbles by the total number of marbles which would be 8/18. For the 2nd probability, we need to remember that we have already removed 1 blue marble so that the number of blue marbles remaining is now 7 and the total number of marbles is now 17 to give us 7/17. We would repeat this process to get the third probability and then multiply all the probabilities together.