A marble shop contains 6 blue marbles, 7 red marbles, and 7 green marbles. If 4 marbles are purchased at random from the shop, what is the probability that the 4 marbles will be blue?\nOptions:\n(A) 5/19\n(B) 9/20\n(C) 1/57\n(D) 15/57\n(E) 15/684 Let's think first. Stream of consciousness:
User
It doesn't matter which type of card you choose, so:\nProbability of choosing 1st card: 6/20\nProbability of choosing 2nd card of the same type: 5/19\nProbability of choosing 3rd card of the same type: 4/18\nMultiply and you get 1/57
So, the answer is (C).
Assistant