Question: A card shop contains 5 birthday cards, 4 holiday cards, and 3 graduation cards. If three cards are purchased at random from the shop, what is the probability that the three cards will be graduation cards?
Options:
(A) 1/33
(B) 6/264
(C) 1/44
(D) 1/264
(E) 1/1320 Let's think first. Some random reasoning:
It doesn't matter which type of card you choose, so:
Probability of choosing 1st card: 3/12
Probability of choosing 2nd card of the same type: 2/11
Probability of choosing 3rd card of the same type: 1/10
Multiply and you get 1/264 The final answer: (D).