A card shop contains 10 birthday cards, 10 holiday cards, and 9 graduation cards. If three cards are purchased at random from the shop, what is the probability that the three cards will be of the same type?\nOptions:\n(A) 3/29\n(B) 12/58\n(C) 12/840\n(D) 7/841\n(E) 12/841 Think first, then make a decision. Some random thoughts:
User
It doesn't matter which type of card you choose, so:\nProbability of choosing 1st card: 1\nProbability of choosing 2nd card of the same type: 4/29\nProbability of choosing 3rd card of the same type: 3/29\nMultiply and you get 12/841 So the answer is (E).
Assistant